Big update to structure

In this commit I restructed source (a bit) a again.
- Added Namespaces and stopped using that much classes with only Shared
elements
- Added "base" classes for Accounts, NPC, Tilesets, Players and Maps
- Finished map overlay system
- Fixed some Out of Range errors in Editors
- Merged all split core map classes to one file (but not to one class of
course)