One small change that was supposed to be in 5a6c18a086 but didn't make
it into the patch version that got merged, and removal of some long-dead
code.
phan objected to the use of new $class without being explicitly
reassured that $class is, in fact, a string. I don't know why.
Change-Id: Ifa00c59ab4464109414f21db37e3a6db21decdf3
100% test coverage of code that appears to be working and used, in both
LockManagerGroupFactory and also LockManagerGroup. Where possible I
wrote it as unit tests. One preexisting code path seems to be broken and
I marked the test as skipped. Two methods look unused and perhaps not
especially helpful, so I didn't write tests for them yet in case we want
to just get rid of them instead.
Change-Id: Iaa7354f31c451b87773468609c674a3bf1d4382f
