Add better control over expression timeouts.
* //timeout command can be used to change player's current timeout.
* Config now also has a max timeout, can be bypassed with permission
* Timeout of < 0 will let expressions run indefinitely.
* Said expressions won't run on a separate thread, slightly reducing the
overhead from context switching. For large //gen commands, for example,
this can actually increase speed.
- Move Vector, etc. into `.math` package
- Drop many methods that will be auto-promoted anyways, eg. with
`divide(int)` and `divide(double)` the first is now gone.
- Take Block vectors into their own class hierarchy
- Make it clear throughout the API what takes blockvectors
- many more improvements
