Update for 1.7.0 release notes.

RELEASE_NOTES.adoc

@@ -3,25 +3,25 @@ ifdef::env-github[]
 :important-caption: :heavy_exclamation_mark:
 endif::[]
 
-= RELEASE NOTES FOR NNG v1.7.0 (DRAFT/IN PROGRESS)
+= RELEASE NOTES FOR NNG v1.7.0
 
 This document has the following sections:
 
 * Notable Changes
 * End of Feature Announcements
 
-== Notable Changes (since 1.5.2)
+== Notable Changes
 
 A new compile time setting, `NNG_MAX_POLLER_THREADS` is introduced,
-with a default value of 8.  Will limit the number number of threads
-used for pollers that are multi-threaded (currently only Windows).
-Additionally for single core systems only two threads will be started
+with a default value of 8, and will limit the number of threads
+used for pollers that are concurrent (currently only Windows).
+Additionally, for single core systems only two threads will be started
 instead of four.
 
 A new supplemental API, nng_id_map(3), is made available.
-This exposes the
-internal ID hash API NNG uses mapping integer IDs (like socket IDs)
-to data structures.  It also brings back support for 64-bit IDs.
+This exposes the internal ID hash API NNG uses mapping integer IDs
+(like socket IDs) to data structures.
+It also brings back support for 64-bit IDs.
 See bug #1740.
 
 Setting the `NNG_OPT_RECVMAXSZ` setting no longer affects pipes
@@ -53,6 +53,12 @@ often we check for expired requests.
 Various minor documentation fixes were made, some contributed by
 Patrik Wenger <[email protected]>.
 
+A new ability to override compile-time settings for thread counts
+is available.  This facility is considered experimental, and is not
+documented in manual pages -- and is subject to change without notice.
+Please see nng_init_set_parameter() in the nng.h header file.  The
+values that can be tuned are listed there along with comments
+describing their use.  See bug #1572.
 
 == End of Feature Announcements