Add support for the /EP argument to clang-cl

This maps the /EP argument to both -E and -P.

Patch by Ehsan Akhgari!

Differential Reviion: http://reviews.llvm.org/D4133

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@210935 91177308-0d34-0410-b5e6-96231b3b80d8
Copy the documentation of -fstandalone-debug from the man page to the user
manual.

rdar://problem/17307006

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@210936 91177308-0d34-0410-b5e6-96231b3b80d8
Make these two words equally bold.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@210938 91177308-0d34-0410-b5e6-96231b3b80d8