Refactor the compiler arguments processing
Use CompilationDatabase from libclang
Use a context manager to handle working directory changes. Needs python 2.6.

Python 2.5 can be supported if we add the appropriate import from future.
Revert "Don't allow duplicate entry in the completion popup."

This reverts commit 53462d915fcd4ae805d69eb6ff7ba104d390a5a1.

That was causing issues when snippets were disabled.
Refactor the compiler arguments processing
Remove a workaround due to broken cindex.py iterator
debug mode: Print clang command line for parsing
debug mode: Print clang command line for completion
Merge branch 'cdb_v5' of git://github.com/Arnaud-de-Grandmaison/clang_complete into cdb
Merge branch 'print_command_line' of git://github.com/tobig/clang_complete into tobig

Conflicts:
	plugin/libclang.py