New map generator added (and SQLite, messed up the commits at that time...) (import from temporary git repo)

Made a proper queued thread to client for handling some block mesh updates. Also made client mutex-free to allow easier adding of new stuff.

Modified block mesh generation to have clearer input and output. Instead of being a messy object oriented cludge, it now is a messy cludge with separate parameters.

--HG--
rename : data/light.png => data/cloud.png

--HG--
rename : src/licensecomment.txt => licensecomment.txt