* adds README to extlib/
* changes javascript to lgpl
* also fixes the agplv3 text so that it says "agplv3 or later"
* moves license files into licenses/
* adds lgplv3 license
* changes COPYING to explain licensing for all of GNU MediaGoblin
* adds design decision regarding why we picked the licensing we did
* adds CC0 and AGPLv3 texts
* removes licensing bits from hacking howto--we should put that somewhere
else
