Build message_lib only after message generation

On faster machines, the makefile generated by cmake will thread quite a lot, and will attempt to compile messages_lib before the header files have been generated, failing the build.

This will force make to wait for the message generation to complete.
Move default affordances values into source file

I really couldn't tell you exactly why this was failing builds on 32-bit Fedora, but in any case this fixes it.
Merge pull request #1 from cottsay/master

Fix Fedora build errors