If you ever want to run a piece of code on a timed interval, or want to wait
a few seconds, you don't have to rely on timing tricks, as Hilbish has a
timer API to set intervals and timeouts.

These are the simple functions `hilbish.interval` and `hilbish.timeout` (doc
accessible with `doc hilbish`). But if you want slightly more control over
them, there is the `hilbish.timers` interface. It allows you to get
a timer via ID.

# Timer Interface
## Functions
- `get(id)` -> timer: get a timer via its id
- `create(type, ms, callback)` -> timer: creates a timer, adding it to the timer pool.
`type` is the type of timer it will be. 0 is an interval, 1 is a timeout.
`ms` is the time it will run for in seconds. callback is the function called
when the timer is triggered.

# Timer Object
All those previously mentioned functions return a `timer` object, to which
you can stop and start a timer again.

An example of usage:
local t = hilbish.timers.create(1, 5000, function()
	print 'hello!'
end)

t:stop()
print(t.running, t.duration, t.type)
t:start()

## Properties
- `duration`: amount of time the timer runs for in milliseconds
- `running`: whether the timer is running or not
- `type`: the type of timer (0 is interval, 1 is timeout)

## Functions
- `stop()`: stops the timer. returns an error if it's already stopped
- `start()`: starts the timer. returns an error if it's already started