More efficient filtering

* $players is now an ID => name mapping
* Offline data is updated after every non-"offline" request
* Use serialize() for offline data
Cache into file

* Automatically caches for 5 minutes
* Remove Steam users who don't own PD2 for now
<abbr> underdash
Temp hack for trying other games ;)
Stupid undefined achievement
Quickfix for magical int cast
Merge pull request #2 from Southpaw018/deagle2

hai thar