Finalized 'Mitocheck movements':

- added some missing parts of the RndWlk (the part around mean step size distribution)
- configuration that enables Mitocheck-like behaviour moved from 'testing' section into the 'cell' one
- following the Mitocheck-like behaviour during simulation is no longer communicated as a "TESTING MODE"

M    config/config-middleVOI-lowSNR.ini
M    config/config-smallVOI-highSNR.ini
M    config/config-711extVOI-highSNR.ini
M    config/config-smallVOI-lowSNR.ini
M    config/config-middleVOI-highSNR.ini
M    src/cell.cpp
M    src/cellScm.cpp
M    src/cell.h

Added some more debug to figure out why we are getting some rendering error.
(error msg: pixelShift has negative coordinates)
M    src/toolbox/bp_lists.cpp