Added a lot nicer movement of cells. It is based on considering cell

polarity (movement goes in this direction) and velocity of movement
(ability to rotate increases with velocity).

M    src/cell_08_G2Phase.cpp	- new movement code
										- corrected bug when cell is forced to stay
										  on the current position

M    src/cell.h			- typo in docs
M    src/cellSOFA.cpp	- debug report change, word 'doing' is reserved for 'greping' logs