Misc fixes, added event/update API to module manager

Module manager now allows the registering of OnUpdate and OnEvent
scripts which pass the module as self. ModuleManager handles
events/updates which are set in active state and then disabled
automatically. The module only has to register/unregister when it wants
to stop executing the module.

Moved activation of modules based on stored state to separate function
called on PLAYER_LOGIN allowing all modules to load before modules can
begin hooking calls.

re-scoped EventManager to be in the EventHorizon table rather than
local.