[PATCH] Clang Rename Tool

[Manuel Klimek]

Submitted as r215839. Note that
a) I had to do a couple of changes for this to compile without warning with latest head
b) I fixed the newFrontendActionFactory problem, please take a look how that works
c) the code is still grossly undertested; the next step will be to get test coverage up so people can work with the code; I just looked at a few places in USRFinder, and added FIXMEs; note that you'll need to do that for the rest of the code

Possible ways to add enough tests:
1. get a good test coverage tool (although that will still miss a lot, but will be a good first indicator)
2. reverse-TDD your code:
a) comment out all the code (*ALL* the code); 
b) comment in enough code to make all tests pass (not that if you only need a single part of if (A || B), leave the part you don't need commented out (for example: if (A /* || B*/))
c) write test that forces you to uncomment part of the code
d) repeat until all your code is commented back in

If you have problems writing a test, please let me know.

http://reviews.llvm.org/D4739