First version of clang parser

Hi, 
the clang paser is now in a semi usable state. Together with the clang_integration branch from
https://github.com/jmachowinski/orogen it is possible to generate correct tlbs for base types.

Note that there are still some hard coded paths in 
bindings/ruby/lib/typelib/clang.rb.

Please test and review these changed.
Greetings
   Janosch


>
> The problem with the list of names is, that they would need to go over the
> command line.
> And passing any complex string over the command line, expecially if it
> COULD contain spaces
> is a pain. Therefore the save/load mechanism
>
??? Just call system with each argument separated instead of as a single
big command line. Then there are absolutely zero ambiguity. I've just
spotted it. You NEVER call system with a single string, unless you really
want to pass a shell command. Exactly because of how fragile it is, what
you do is:

```
cmd_line = Array.new
cmd_line << "-opaquePath" << path_to_opaque_file
system(path_to_clang_importer_tool, *cmd_line)
```

Result guaranteed.