Bugfixes -- frame timout

Two fixes related to frame timeout processing:

• Allow disabling frame timeout in simulation by setting None (null in .yaml) as the max_frame_time config value. This fixes #15.
• Fix erroneous duplication of frame timeout value for all frames. Timeout is only prolonged for the first frame -- initialization requires more time than the following frames. Sim property files are updated to reproduce earlier behavior with erroneous timeout duplication