Dev: register conditions inside Conditions class rather than in OtherDropsConfig

* advantage being that it's easier to locate and more "encapsulated"
Dev: 1.7.2 - add unimplemented methods in PlayerWrapper
Add: Basic 2d distance check (only > than) - needs to be enhanced with 2d vs 3d & <, =, <>.

* usage - distance: 50@10;60;20 # distance must be more than 20 units from point x=10, z=20 (y coord is ignored for now).
* needs more testing & comprehensive error checking (eg. negative distance?)