Fix the output of UUIDMigration#getIdentificationFor(Player)

Because this method returned a String instead of a UUID, Pet#getOwner()
did not work properly: `ownerIdentification` was always a String as of
Pet.java:92
Merge pull request #251 from eueln/petgetownerfix

Fix the output of UUIDMigration#getIdentificationFor(Player)
Version to 2.3.1
Version to 2.3.2-SNAPSHOT
Actually build everything into the jar file
Reduce plugin size and resolve incompatibilities with other plugins
Version to 2.3.2
Version to 2.3.2-SNAPSHOT
._.
/me facepalms
Cast all the things properly
Test Jenkins stuff
Use the correct path
Version to 2.3.3
Update UUID migration tools
Use stored owner identification for pets. Fixes #252
Why are we returning null here? :(
Add migration for SQL tables. Fixes issues related to #255
Check if it already is a UUID
Update to CraftBukkit 1.7.9