Updated README.

README.md

@@ -1,3 +1,4 @@
+# Overview
 The [MQTT-SN](https://www.oasis-open.org/committees/download.php/66091/MQTT-SN_spec_v1.2.pdf) 
 protocol is a sibling of [MQTT](http://mqtt.org). While **MQTT** is designed to be 
 used over a **reliable stream** transport protocol (such as TCP/IP), the **MQTT-SN**
@@ -14,15 +15,15 @@ and **without errors**.
 
 This repository provides **single threaded**, **asynchronous**, **non-blocking**, easy to
 use, suitable for **embedded** platforms, well documented libraries 
-of MQTT-SN client and gateway, which are
+of MQTT-SN **client** and **gateway**, which are
 completely generic and allow usage of MQTT-SN protocol over any I/O link. See 
 details below.
 
 # Client Library
 This repository provides the MQTT-SN **client** library. It is implemented 
-using C++(11) programming language, but provides **C** interface. The library's
+using C++(17) programming language, but provides **C** interface. The library's
 code doesn't use [RTTI](https://en.wikipedia.org/wiki/Run-time_type_information)
-or exceptions, but by default
+or exceptions. By default
 the library's implementation uses C++ STL data types, such as 
 [std::string](http://en.cppreference.com/w/cpp/string/basic_string) and 
 [std::vector](http://en.cppreference.com/w/cpp/container/vector). However,
@@ -32,18 +33,23 @@ refer to [doc/custom_client_build.md](doc/custom_client_build.md) for instructio
 how to do it. 
 
 The doxygen generated documentation of the library with its full tutorial can
-be downloaded from the [release artefacts](releases).
+be downloaded from the [release artefacts](releases) or browsed
+[online](https://commschamp.github.io/cc_mqttsn_client_doc).
 
 # Client Applications
-The [Client Library](#client-library) described above is I/O link agnostic,
-it allows to do any additional packatisation of the sent data to allow
-correct delivery of the messages. This repository also provides a couple of
-MQTT-SN **client** "publish"(**cc_mqttsn_pub_udp**) and "subscribe" 
-(**cc_mqttsn_sub_udp**) example applications, which use
-UDP/IP as its datagram transport layer. These applications are also using
-[Qt5](https://doc.qt.io/qt-5/) framework for their operation. It means that if
-proper QT5 libraries are not installed or can not be found, these applications won't
-be compiled.
+This repository also provides extra utilities (example applications) which
+use the [client library](#client-library) described above.
+
+* **cc_mqttsn_gw_discover** - Discover available gateways client application
+* **cc_mqttsn_client_pub** - Publish client application
+* **cc_mqttsn_client_sub** - Subscribe client application
+
+These applications use [Boost](https://www.boost.org) libraries,
+([boost::program_options](https://www.boost.org/doc/libs/1_83_0/doc/html/program_options.html)
+to parse the command line arguments and
+[boost::asio](https://www.boost.org/doc/libs/1_83_0/doc/html/boost_asio.html) to run
+the events loop and manage network connection(s)). Currently only UDP/IP network
+connection type is supported.
 
 # Gateway Library
 Just like the [Client Library](#client-library) allows additional data
@@ -53,36 +59,27 @@ which provides the required core functionality and allows implementation of any
 gateway application, suitable for the type
 of I/O link to the client(s) being used.
 
-This repository provides such a library. It is implemented using C++(11)
+This repository provides such a library. It is implemented using C++(17)
 programming language and provides both **C++** and **C** interfaces to use.
 The gateway uses [v3.1.1](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.pdf)
 of the MQTT protocol to connect to and communicate with the broker.
 
 The doxygen generated documentation of the library with its full tutorial can
-be downloaded from the [release artefacts](releases).
+be downloaded from the [release artefacts](releases) or browsed
+[online](https://commschamp.github.io/cc_mqttsn_gateway_doc).
 
 # Gateway Applications
-The [Gateway Library](#gateway-library) described above is I/O link agnostic,
-it allows to do any additional packatisation of the sent data to allow
-correct delivery of the messages. This repository also provides the 
-MQTT-SN gateway(**cc_mqttsn_gateway_udp**) example application, which uses
-UDP/IP as its datagram transport layer. The application also using
-[Qt5](https://doc.qt.io/qt-5/) framework for its operation. It means that if
-proper QT5 libraries are not installed or can not be found, the gateway example
-application won't be compiled.
-
-# Spec Deviations
-There are a couple of deviations from official MQTT-SN 
-[v1.2](https://www.oasis-open.org/committees/download.php/66091/MQTT-SN_spec_v1.2.pdf)
-spec.
-
-- The [client](#client-library) does NOT send **GWINFO** messages as a response
-to **SEARCHGW** message from other clients, on behalf of the gateway.
-- The [gateway](#gateway-library) sends **GWINFO** as a response to the 
-**SEARCHGW** message directly to the requesting client, not broadcasting it
-like the protocol specifies.
-
-All other behaviour is implemented as specified.
+This repository also provides extra applications which
+use the [gateway library](#gateway-library) described above.
+
+* **cc_mqttsn_gateway_app** - Transparent gateway application.
+
+These applications use [Boost](https://www.boost.org) libraries,
+([boost::program_options](https://www.boost.org/doc/libs/1_83_0/doc/html/program_options.html)
+to parse the command line arguments and
+[boost::asio](https://www.boost.org/doc/libs/1_83_0/doc/html/boost_asio.html) to run
+the events loop and manage network connection(s)). Currently only UDP/IP network
+connection type is supported.
 
 # How to Build
 Detailed instructions on how to build and install all the components can be