Updated stormy desert map
Merge pull request #74 from esper/master

Fixed two crashes.
Merge branch 'master' of github.com:TheJosh/chaotic-rage
Update skybox loader to handle more error conditions
Add skybox to stormy desert

from http://www.3delyvisions.com/skf1.htm
Stormy desert skybox
Rejig heightmap into it's own class
Move heightmap load to at map load time

This allows reasonable error reporting.
Also, re-enabled the power-of-two check with all maps valid again
Except the crappy ones in the 'test' module.
Actually *use* the 'data' and 'texture' heightmap config fields
Use JPG instead of PNG for therlor valley terrain

It's a smaller file
Issue #75. Makefile detects if included headerfiles have changed.
Sources and more info:
http://gcc.gnu.org/onlinedocs/gcc-4.8.2/gcc/Preprocessor-Options.html
http://www.gnu.org/software/make/manual/html_node/Include.html
http://stackoverflow.com/questions/16221805/why-isnt-make-detecting-changes-in-header-dependencies/16221973#16221973
Merge remote-tracking branch 'upstream/master'