Forgot to add changes to trees source texture.
Build process updates .blend files in a special directory.

This means that updating the Blender version doesn't mess up
version control of the files. Also, the build process has been
cleaned up a little to make better use of make's ability to
recognise files that have changed.
Added project file for Kate editor.
Fixed compilation order and directory issue.
Added instructions for building.
Reorganised Makefiles to be thread-safe and in the right order.
Fixed compilation of grass.

Needs full path or relative paths break on save.
Also, fixed inclusion of version files.