[Freeciv-Dev] A reorganization (PR#643)

[Thue <thue@xxxxxxx>]

This creates the file diplomats.[ch] with 1400 lines of selfcontained code.
It also removes the file unitfunc.[ch], and moves the remaining code into 
unittools.[ch] (the distinction between the two was undefined, so no need to 
have them both).
The combined unittools.c was then cleaned up and sorted, a few functions 
moved to better files.

This is strictly a reorganization; not a single line of real code changed.

http://hjem.get2net.dk/thue_janus_kristensen/diplomats.diff.bz2

-Thue