Don't abuse of memory in benchmarks
Merge branch 'master' of github.com:ContinuumIO/blz
Protect against updating the mode in chunks for in-memory container
Actually remove the on-disk column directory during delcol.  Fixes #8
Merge branch 'master' of github.com:ContinuumIO/blz
Getting ready for releasing 0.6.2
Post 0.6.2 actions done.