Feature to enable asynchronous event driven of network events
replace 111 error code literal with ERRNO_CODES.ECONNREFUSED as prompted by juj
Improve callback mechanism to allow an arbitrary userData pointer to be passed during callback registration that will subsequently be passed to the callback
Improve error handling on getsockopt when a level other than SOL_SOCKET or an optname other than SO_ERROR is supplied as per the conversation with juj
Make debug message for the default logging on error handler use Module.printErr rather than Module.print as suggested by juj
Add some more documentation to emscripten.h to explain that the JavaScript error callback takes an array containing the file descriptor, error code and error message.
Support webkit gamepad api
Fix CMAKE_FIND_ROOT_PATH

This allows projects and libraries using CMake to automatically find include directories and library files in the emscripten system directory. I am unsure why it was set to `${EMSCRIPTEN_ROOT_PATH}/cmake` before, but I tested it and it didn't work until I changed `cmake` to `system`. `CMAKE_FIND_ROOT_PATH` is documented [here](http://www.cmake.org/Wiki/CMake_Cross_Compiling#Searching_and_finding_external_software).
Refactor sdl_canvas_size

There's no need to load all the OpenGL stuff to
test canvas size and resizing.
add SDL_GetRGB and SDL_GetRGBA
add SDL_putenv
add myself to AUTHORS
Modify server on error to be consistent with the client on error
fix the build failures (we should only delete the jcache directory, not everything)
Add missing libc files to the build.
Merge pull request #2459 from jonessen96/fix-cmake

Fix CMAKE_FIND_ROOT_PATH
Don't increment result, return 1 on success or 0 on failure
Merge pull request #2460 from gsathya/clean_canvas_size

Refactor sdl_canvas_size
Review changes
assert on memory initializer region not being written to before it is applied