Add a timelimit variable

[cswhite2000]

Adds a match scoped timelimit action

Behaves like the command

Example:

<timelimit duration="10s" result="objectives"/>

All attributes are optional.

This has all of the same optional arguments as the command.

For @zzufx

[Pablete1234]

Besides the two minor things i mentioned, looks good to me

However, i thought we were going to have timelimit actually implemented as a variable instead of an action, which gives the flexibility to change it more arbitrarily (eg: +120 for adding 2 mins to tl)

[cswhite2000]

However, i thought we were going to have timelimit actually implemented as a variable instead of an action

Right, I forgot we had this discussion
Probably would be better to implement it that way

[cswhite2000]

Switched to a timelimit variable with example usage:

<variables>
	<timelimit id="tl_2"/>
</variables>

...
in actions:
<set var="tl_2" value="60"/>

Other behaviour:

Negative time limits cancel the timer.
A time-limit of 0 will instantly end the match