Remove trailing whitespace
awn-settings: Fix a typo
Replace problematic vala sources with C source generated by valac-0.12

valac-0.12 dependency forces us to build on Ubuntu Precise environment
and thus interferes with C++ conversion. Replacing the files that depend
on valac-0.12 with the generated code is an temporary solution until we
rewrite it in C++.
Compile the valac generated files with a C++ compiler