Upgrade to clang 3.4

Replace headers, lib files and dll for LLVM/Clang with ones from a build off trunk
Make use of the new SourceRangeSkipped callback to find out which lines have been skipped by the preprocessor
Fix header search path addition to make it work with the latest API
Fix tests broken because the SourceRangeSkipped callback includes the lines containing the directives. Modified line numbers in the tests
Merge branch 'clang_upgrade'
Commit missing Clang/LLVM headers and libs
Add README and gitignore
Bump up version number to 0.3.0