Specify the flag '-std=c++11' for auto-complete-clang
Make the variable 'ac-clang-flags' buffer local
Use a precompiled header file when completing
Automatically create the specified precompiled header if not exist
Recreate the precompiled header if its source file is newer than it
Use my patched version of auto-complete-clang temporarily
Define the function ac-clang-compile-header