[PATCH] Fix bug 20892 - clang-format does not handle C-style comments

[Roman Kashitsyn]

> I am against supporting "///" and "/**" style comments

That's reasonable. I will remove all that nontrivial logic and replace it with simple comparisons against `// clang-format on` and `/* clang-format on */`.

http://reviews.llvm.org/D5309