Merge pull request #330 from dorkster/fixes

Add desktop file and svg icon
Added simple setup steps
Add detailed Linux build/install instructions to README
Change "Installation" to "Building and Running" in README

The instructionsaren't limited to system-wide installation.
Merge pull request #333 from dorkster/docs

Add detailed Linux build/install instructions to README
Added MAP_ONLY tiles to tiled_collision.png
Merge pull request #340 from makrohn/extratiles

Added MAP_ONLY tiles to tiled_collision.png to implement https://github.com/clintbellanger/flare-engine/issues/721