Integrated lock tree into the transactions.
    Allocated on create
    unlocked on abort/commit
    transaction keeps track of which lock trees it owns locks in
Started working on integrating c_get functions.
Modified locktree API to make it easier to use both dupsort and nondup dbs
Fixed tests to work with new locktree API.

git-svn-id: file:///svn/tokudb@2140 c7de825b-a66e-492c-adef-691d508d4ae1