git-svn-id: https://bucket.mit.edu/svn/nilm/nilmdb@10642 ddd99763-3ecb-0310-9145-efcb8ce7c51f
git-svn-id: https://bucket.mit.edu/svn/nilm/nilmdb-new@10336 ddd99763-3ecb-0310-9145-efcb8ce7c51f
and ensure that all function calls happen from within the context of a single thread. git-svn-id: https://bucket.mit.edu/svn/nilm/nilmdb-new@10334 ddd99763-3ecb-0310-9145-efcb8ce7c51f