remove declarations of fcns that we were moved

fixes up a4b194c0794d360dc6eff5c464c6634941dff5da
set travis back to gcc 4.6 version

The gcc-4.8 patch requires travis to download and install gcc-4.8
from an ubuntu ppa. This takes a few mintues and the gcc build is
already fairly close to the timelimit, so this change can push
some builds over the edge. Since it doesn't seem to be strictly
necessary right now, I comment out the code for v 4.8 install.
Merge branch 'master' of git://github.com/wesnoth/wesnoth