give throttle credit for time served (time spent outside of Write routine).
Switch to MONOTONIC clock.  Remove imm_micros from background compaction time tracking.
correct throttle_end from int64_t to uint64_t
manually add travis config to this branch ... sooner or later we will starting getting this on new branches automatically.
update this branch with lesson found on different branch:  my_batch can be NULL
Merge branch 'mv-throttle-4' of github.com:basho/leveldb into mv-throttle-4
correct math regarding batches.
give throttle credit for time served (time spent outside of Write routine).
Switch to MONOTONIC clock.  Remove imm_micros from background compaction time tracking.
correct throttle_end from int64_t to uint64_t
update this branch with lesson found on different branch:  my_batch can be NULL
correct math regarding batches.
resolve conflicts because git is pathetic
Merge pull request #93 from basho/mv-throttle-4

Mv throttle 4
Merge branch 'master' into mv-flexcache
incremental commit to allow pull of current master for merge