Switch the license to be LGPLv2/later, with small parts still remaining as GPLv2/later, by agreement of major contributors

The huge item definition and item namespace unification patch (itemdef), see http://c55.me/minetest/wiki/doku.php?id=changes:itemdef

Make Connection::Receive return the data via a SharedBuffer reference, so the caller doesn't have to choose the right buffer size in advance.

Conflicts:

	src/test.cpp

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