concept code for dynamic block size.  works well with 2T load on 32G machine.  needs work for production.
safety checkin:  code compiles but zero testing ... and code incomplete.
code complete ... testing starts
clear warning message
Merge branch 'mv-dynamic-block-size' of github.com:basho/leveldb into mv-dynamic-block-size
fix two warnings
tunings based upon first 3 big tests
add current_block_size_ member variable to use with non-critical point compactions.  address unrelated concern about file numbers and threads ... looks unnecessary, but safer
add some timers to smooth both step up and step down
Address code review comments.
Merge pull request #111 from basho/mv-dynamic-block-size

Mv dynamic block size