Split IGameCallback to reduce memory required to debug compilation.
Move CPrivilagedInfoCallback, IGameEventCallback and CNonConstInfoCallback to IGameCallback.h
Clean up.
Rename new files.
It compiles with -gdwarf-3
Merge pull request #2 from o01eg/my-diff

Split and clean up for IGameCallback.
Fix for linking in MS VS and CodeBlocks.
Merge pull request #3 from o01eg/my-diff

Fix for linking in MS VS and CodeBlocks.
One more fix for MVS compilation
fixed possible nullptr dereference

* Fixed a switch() statement in InfoBoxHeroData::getValueText that
  could result in nullptr dereference. If 'type' was HERO_MANA and
  'hero' was nullptr, a fallthrough would occur to HERO_EXPERIENCE,
  where 'hero' would we be dereferenced.
* Fixed line endings.