libcore|Math: Random numbers
libcore|RecordAccessor: Added a has() method
Client|Loop: Length of current tick can be queried
libgui: Storing animation data in ModelBank
libdoomsday|Thinker: Private data is notified of mobj state changes
Model Renderer|Client: Set up state-based animations for loaded models

The animation lookup is stored in the model bank.
Client|Mobj|Refactor: Working on state-based animations

ModelRenderer's animation sequences are now used by the mobj private
data to trigger animations. Animations are advanced as the mobj
thinks.

Also moved particle generator spawning into ClientMobjThinkerData.
Cleanup
Refactor|Model Renderer: Revised definition syntax for state triggers

It is more intuitive if the state is the parent record. Multiple
possible sequences can be defined per state (maybe with different
probabilities). One sequence may also be used in several states.