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.
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.
add pkg-config files for some supported libraries
Exit from src/compiler.js with a nonzero return code on exception. Replaces #2453.
Remove ".dll" from DYNAMICLIB_ENDINGS, since on Windows one never links to a .dll file directly (e.g. via a command line -lFile -> libFile.dll) either, but instead separate import libraries with suffix .lib are used. Note that for crosscompiling, it is _not_ recommended to generate Emscripten static bitcode libraries with suffix .lib, but instead generating files with suffixes .bc (or .a) is better form.
Add support for GL_HALF_FLOAT_OES in getTexPixelData.
Remove bad assert() in GL library: GL interop layer should never throw on user errors, only on internal errors that are an implementation bug.
Add comment explaining why .dll is not present in DYNAMICLIB_ENDINGS.
Merge pull request #2498 from juj/no_link_dll

Remove ".dll" from DYNAMICLIB_ENDINGS.
simplify some code and remove a frequent, unnecessary null pointer check in the generated javascript
move check for noExitRuntime into exit(), and fix up tests
fix process.exit call for closure
generate libc/libc++ using multiple cores