New teeterl; 4x faster

Three months ago I decided to give teeterl a once over. The goal was to make it faster, order of magnitude faster. Today, the new teeterl version has become mature enough to run estone_SUITE and produce meaningful performance measurement printout. The result: it is almost 4 times faster than earlier teeterl. Not 10x, but definitely on the right track. BEAM is still a distant performance star boasting more than 2 times more estones.

The new version of teeterl has a goodish bit under the hood. The most noticeable are the new partial, generation-aware garbage collector and the fact that teeterl VM is now register-based.

The new teeterl can not do much more than run a few test suites now. Nevertheless I will release the source of github as soon I figure out how to push it into existing 'teeterl' repo without destroying the previous version.