setup elemate with glow

get the glow dependencies, see also https://github.com/hpicgs/glow

environment setup on windows:

• GLEW_HOME - glow 1.10 root folder, copy the release (x64) binaries and libraries from their subfolders directly to bin and lib, otherwise the cmake scripts will not find them
• GLM_HOME - glm >=0.9.3 root folder
• GLFW_LOCATION - glfw 3.0.3 install path. You have to setup glew before compiling glfw.
• GLOW_DIR - glow install path, with slashes, NOT backslashes!
• add the binary folders to your PATH, or copy all the binaries (dll's) to one 3rdparty binary folder that's in your PATH
• make sure that there is no other glew32.dll (version <=1.9) somewhere in your path folders, otherwise the binary loader will complain about missing _gl* functions

compiling glow

• clone glow from https://github.com/hpicgs/glow.git
• checkout glow-v0.2.1 tagged commit (a56466c8b0d36c3895ab6ce7edf0e48ef65e4531)
• cmake: set OPTION_DISABLE_EXAMPLES, set CMAKE_INSTALL_PREFIX to your glow install path
• build and install in debug and release

now you should be able to cmake and build the glow version of elemate