[h3mlib] Conversion: Improve conversion of some WoG maps to not cause crashes

[potmdehex]

The current WoG conversion hasn't been worked on/tested much and while it seems to succesfully convert many maps so that they can be opened in the HD Edition map editor, some of the maps crash when started in HD Edition.

Code: https://github.com/potmdehex/homm3tools/blob/master/h3m/h3mlib/h3m_conversion/convert.c

Done definition: No converted WoG maps should crash when started by HD Edition.

Note: The h3m conversion code in h3mlib was mostly written in a rush a few days before HD Edition's release so it is quite messy.