Added:

- cells can enter G2 phase atomic function again and again
  now even when SOFA is enabled in the CMake
  (so simulation can "interleave the cells", unlike "one does all after another")

- cell movement routine can now rescue cells when in collision

M    src/cell.cpp					- Cell::DoNextPhase keeps cell running in G2
M    src/cell.h					- when SOFA: added slsRotation and slsTranslation
										  (which used to be local in the G2)
M    src/cell_08_G2Phase.cpp	- added code looking for smallest translation when cell
										  has 'mustMove' true