here we detect issue #35
I meant issue #31
Merge branch 'master' into nczempin

Conflicts:
	enemy.lua
Merge branch 'master' into nczempin

Conflicts:
	enemy.lua
Added some additional settings screens and pushed the shader settings
down. This fixes issue #51
switch between small (800x600) and [moderately] large [1280x720) resolutions. this partially fixes issue #54. I will get the fullscreen option setting working too, but actually choosing resolutions from a will be done in a separate issue, because it involves a whole new widget type.
cleanup
enabled resolution switch and fullscreen toggle
Add map cursor
building a tower costs mass
removing towers increases available mass
get some fixed starting mass and allow the initial towers to be essentially free.
laser shots cost energy
Merge branch 'master' into nczempin

Conflicts:
	enemy.lua
	state/settings.lua
	state/settings_video.lua
	state/settings_video_display.lua
	state/settings_video_shaders.lua
repaired merge-cockup