Some more useful functions

Some of these need categorizing though!

Added GetDurationFromString which returns the time in seconds from a
basic string like "5 days" or "7 weeks".

Added IsValidUsername, does what you expect.

Added CancelPlayerMovement which uses 3 methods to stop a player from
moving and playing animations and ensure it syncs to others.

Added IsPlayerIdle which checks if a player is just doing nothing while
playing generic idle animations such as standing, holding a weapon and
breathing.

Added GetCameraModeName, not sure how it's really useful to be honest.

Added CreateTimedObject for creating objects that die after some time
(such as particles).

Added IsPointInMapBounds for checking if some coordinates are within the
San Andreas map (6km x 6km).

Added RBGA <> Int conversion functions and IpIntToStr for converting an
IP address integer to a dot-decimal notation string.

Added PickFromList which fills an output array with random numbers
between 0 and the specified max.