Merge branch 'incoming'

Conflicts:
	AUTHORS
Merge branch 'incoming'
do not break on call/invoke to undef; fixes #914
Merge branch 'incoming'
Merge branch 'incoming'
Merge branch 'incoming'
Merge branch 'incoming'
Add ability to use versioned clang libraries

Just like LLVM_ADD_VERSION.
added myself to the AUTHORS
Merge branch 'ag/clang-add-version' of github.com:agladysh/emscripten into agladysh-ag/clang-add-version2