New cell attribute, chrDensities, has been introduced as well as

a some more statistics reporting functions.

M    cell.h						- added Cell::chrDensities,
									- added functions ChrUpdateDensities(), ChrUpdateStats(), ChrReportClosests()
M    cellChr.cpp				- added implementations of the three functions
									- little change in the reports of the ChrRenderIntoPhantoms()

M    cell_06_G1Phase.cpp	- added some debug reports related to the chromosome organization
M    cell_07_SPhase.cpp
M    cell_08_G2Phase.cpp