evas/cserve2: Add font and glyphs loading implementation

evas/cserve2: Add font and glyphs loading implementation
 to cserve2.
Big commit that implements the entire functionality. Besides loading
fonts and glyphs, and sharing the glyph bitmaps with clients, it also
adds:
- new request system, with a much better abstraction;
- new working slaves management;
- slaves can be threads or process now;
- started a debugging and statistics implementation on server.

The image caching part still uses the old request and slaves system, but
should be changed to use the new one soon and get more easily
maintainable.

git-svn-id: svn+ssh://svn.enlightenment.org/var/svn/e/trunk/evas@72699 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33