phase names longer than 16 characters in the dch file yield to bugs / unexpected behaviours

[gdmiron]

https://bitbucket.org/gems4/xgems/issues/23/phase-names-longer-than-16-characters-in #

[sdmytrievs]

Changed GEMS3K and xGEMS API to use an 'unlimited string' with phase and other names (as saved in the dch file).

GEMSGUI can export names of up to 16 characters according to the internal key structure.

Some internal debug and error messages use a 16-character cut-down version of the phase name contained in the dch file.