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.
Updated my e-mail address
Let math functions get lowered to Math.* as they were before.
Remove unnecessary continue statement.
Merge pull request #2484 from waywardmonkeys/fix-math-function-aliases

Fix math function aliases
fully fix other.test_module_exports_with_closure
Merge branch 'patch-1' of github.com:eXon/emscripten into incoming
add RGBA8888 pixel format check in various SDL APIs
add pkg-config files for some supported libraries
add support for ffs libc function.
ressurect optimizeShifts (just in js optimizer and tests), with a fix for ensuring at most one value with unknown lower bits; #2481
re-enable optimizeShifts in non-asm builds; fixes #2481