gl/tileset: Copy without modifications from tileset. Use as a basis for the OpenGL version.
gl/cmd/globe: Copy without modifications from cmd/world. Use as a basis for the OpenGL version.
gl/cmd/globe: Add example tile sets from tile engine tutorial.

ref: http://www.xnaresources.com/?page=Tutorial:TileEngineSeries:1
ref: http://www.xnaresources.com/?page=Tutorial:TileEngineSeries:2

Any copyright associated of the example tile set is held by xnaresources.
gl/tileset: Update to use OpenGL.
gl/cmd/globe: Update to use OpenGL.