Main thing: Corrected bug that rendered nucleoli outside nuclei,

which lead to some rendering issue ("pixelShift has negative values" error).

Typos in the docs were corrected.
M    src/toolbox/collisions.h

Thresholding of the correlation results into a freePositions image prevents
flagging the border pixels as free (=available to occupy).
Removed some ages-long deprecated code.
M    src/toolbox/collisions.cpp

Only added comments/documentation to the parameters of Cell::GenerateNucleolus().
M    src/cell.cpp

Very decent reformating of a small portion of the code.
Corrected bug that prevented second nuclei (after split) to be rendered
when macro ENABLE_NUCLEOLI was disabled.
M    src/cell_04_Telophase.cpp