Adjust .gitignore
Explicitly disable --memory-init-file during emscripten build.
Adjust .gitignore
Use big java heap size when running closure compiler
Fix compilation of asmjs JIT backend against latest upstream
Add an optional "nodebug" include dir that overrides debugging macros.

This is useful for production builds where the debug info (e.g. rpython
tracebacks) is just wasted space.
Merge branch 'master' into rfk/rjs-module