Fix clang frontend for python 3
Merge branch 'fix-clang-py3' of github.com:girving/xdress into girving-fix-clang-py3
Merge branch 'clang' of github.com:xdress/xdress into girving-fix-clang-py3
Fix our libclang copy for clang 3.3 and 3.4
Merge branch 'more-clang-versions' into clang

* more-clang-versions:
  Fix our libclang copy for clang 3.3 and 3.4
Use llvm-config-3.x if llvm-config is not found

Ubuntu users may install a version specific llvm, so that llvm-config
looks like llvm-config-3.4, say.  Thus, if llvm-config doesn't exist,
we try llvm-config-3.5 down to -3.2 in order.

Note that since there does not seem to be a clang equivalent of
llvm-config, this may not solve all problems.

Fix by Kevin Tew <tew@byu.edu>.
Fix clang frontend for python 3

libclang synced from https://github.com/xdress/clang/commit/ba12a91830c6335a594ac7aa4f0f676206732356.
Merge branch 'fix-clang-py3' of github.com:girving/xdress into girving-fix-clang-py3