Add OpenLDAP Lightning Memory-Mapped DB

Also modified by jeffali <hichame.jeffali@cfengine.com>:

    Add LMDB support (TCDB is still the default option)
Adapting CFE locks to lmdb length limit (and fixing unit test)
Do not hash license tracking locks
Make GenerateMd5Hash optional
Make hashing locks optional (only if lmdb is chosen)
Merge pull request #962 from kacfengine/lmdb

Remerge of LMDB after fixing authorship