Optimize (x&A)<<B>>B.

Add an optimization to simplifyExpressionsPre to replace (x&A)<<B>>B with X&A
if possible. This comes up frequently in C++ with bool variables.
Allowed Emscripten to recognize and compile .m and .mm files
(Objective-C and Objective-C++, respectively)
add linpack benchmark
Add myself to the AUTHORS file.
Merge pull request #1204 from sunfishcode/incoming

Optimize (x&A)<<B>>B.
handle ./ in file packaging
support relative paths in -s KEY=@path
properly expand response files in EXPORTED_FUNCTIONS, which is used before compiler.js
remove llvm.global_ctors from libcxx symbols
make file packager closure-friendly
show --help in emcc even if there are other args
Simplified code by using a tuple in combination with `endsWith`.
Merge pull request #1203 from michaeljbishop/objc-support

Allow Emscripten to recognize and compile .m and .mm files
auto-export malloc, needed by file packager
handle globals with no value and no zeroinit
additional embind testing
do not emit resumeException when exceptions are disabled
enable asm.js in embind, with extra reserved function pointers by default
tiny bit more embind testing
silence exceptions during cxa_free_exception