To minimize migration effort, we follow the logic of legacy macro Rel10 and Rel14 used
for conditional compilation of current code.

In the future, they might be changed to accommodate finer software configuration, e.g.
MAKE_VERSION(12,2,0) or MAKE_VERSION(13,1,0) .... etc.

The new 'basic simulator' is now functional.
A proper solution is needed to deal with SIB18/19/21
for the D2D functionality.

UE directory splits, creation of UE-specific files, common UE/eNB files and extraction of UE/common components from eNodeB files. renaming of files to minimize common names across directories (i.e. defs.h, vars.h, extern.h)