Recommit r315738 "[clang-refactor] Apply source replacements"

The fixed commit ensures that ParsedSourceRange works correctly
with Windows paths.

Original message:

This commit actually brings clang-refactor to a usable state as it can now
apply the refactoring changes to source files.
The -selection option is now also fully supported.

Differential Revision: https://reviews.llvm.org/D38402

llvm-svn: 315918