Added 3D randomwalk.

Added the new functionality into the main rnd walk file.
Added a new Get/Set function to the rnd walk class.
M    src/toolbox/randWalk.h

Uses now the 3D walk for "universal cell movement".
M    src/cellScm.cpp

3D-related initialization of the rnd wlk in the cell's constructor.
M    src/cell.h

Added/updated the reports.
M    src/main.cpp

Introduced a new parameter: the anisotropy along the z-axis of the 3D random walk.
M    config/config-middleVOI-lowSNR.ini
M    config/config-middleVOI-highSNR.ini
M    config/config-smallVOI-lowSNR.ini
M    config/config-smallVOI-highSNR.ini
M    config/config-711extVOI-highSNR.ini
M    config-synthHeLa/small_masks/config-synthHela.ini
M    config-synthHeLa/standard_masks/config-synthHela.ini