Parse old Overworld_Data XML tag
Parse Overworld XML tag
Parse XML tag Waypoint.

The savegame loader is now complete.
Use the new savegame loader when ENABLE_NEW_LOADER is defined.
Fix decorators on exception classes.

C++ is really picky about getting the right what() function on
exceptions. These functions must be double-const() and throw(). Uh.
Fix typo
Add debug statement to cSavegame::Load_From_File() and correct that one in cOverworld::Load_From_Directory()