1. Add Engine::dead attribute; if set, the engine will not be run at all (unless explicitly called via () from python or ::action from c++). Useful for temporarily (de)activating engines without having to modify O.engines
2. PeriodicPythonRunner renamed to PyRunner as it is used so often.
3. Add Cell.getVolume() and utils.porosity
4. Check for force&torque NaNs in NewtonIntegrator in debug builds
5. Add --rebuild option which will launch scons before running the simulation itself
6. Some fixes in the HertzMindlin law
7. The qt4 interface will try to open packaged docs, then docs in the source dir and online docs as the last resort.
8. Some fixes in PeriTriaxController (the servo-mechanism) and probably a bug fix in TriaxialStressController (will ask Bruno on the list to confirm the correctness)