Support for .c++ file extension

[tobbelobb]

Hello Compiledb developers!

Could we change

file_regex = re.compile(r"^.+\.c$|^.+\.cc$|^.+\.cpp$|^.+\.cxx$|^.+\.s$", re.IGNORECASE)

into

file_regex = re.compile(r"^.+\.c$|^.+\.cc$|^.+\.cpp$|^.+\.cxx$|^.+\.c\+\+$|^.+\.s$", re.IGNORECASE)

please please pleeeease?

I know .c++ is not a widely used file extension, but if you ever see it in the wild, you would expect the file to contain c++ source code and nothing else, right?

[Thaodan]

PR?

[tobbelobb]

Ok, created one: #108

Closing this issue, we can keep further comments in the PR