Removed command callbacks

This is a very fragile system due to the potential recursive nature
going back and forth across the c++/python boundry and was only used by
burst run. That feature would be better served by making use of a custom
buff which will be implemented in a future iteration.
Fixed issue with sizes/offsets in compression
Merge pull request #599 from apathyboy/crashbug

Removed command callbacks
Merge pull request #600 from apathyboy/transactions

Fixed issue with sizes/offsets in compression