* Separate pruning frequency from timeout
* Pluralize CNShared map: login -> logins
* Increase connection timeout to 15 minutes
* Do not deallocate a nullptr in playerEnter()
* Kill connections rejected by playerEnter()
* Remove redundant inclusions of mutex headers in a few places
* Database.hpp is still the only external include file (moved to db/)
* The header is still uppercase to match its namespace
* db/internal.hpp is the shared header for the DB source files
* Added -Isrc/ compile flag for src-relative include paths
* Hoisted CHDR above CSRC in Makefile (it was bothering me)
* make clean now removes all objects in the subdirectories as well
