This has seen quite some usage and I am not aware of any issues. Also
add a style option to enable/disable include sorting. The existing
command line flag can from now on be used to override whatever is set
in the style.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@253202 91177308-0d34-0410-b5e6-96231b3b80d8