Updates for uuid2

Id columns made to length 37
Merge branch 'master' into wottop/uuid2

Conflicts:
	src/main/resources/db/changelog/changelog-create.xml
	src/main/resources/db/changelog/changelog-update.xml
Merge pull request #528 from candlepin/wottop/uuid2

Switch to using uuid2 instead of uuid to avoid getting the IETF Hibernate warning exception.