Make inactivity timeout configurable

[knabar]

This PR is for issue #1408 and makes the inactivity timeout configurable, so e.g. the controls can be hidden quicker or slower than the default 2000 ms:

<script>
    videojs.options.inactivityTimeout = 5000;
</script>

[gkatsev]

Seems reasonable to me.

[mmcc]

Yep, seems reasonable to me too. Unless @heff has objections, we'll pull this one in soon.

[gkatsev]

Actually, this should probably check the current player's options for inactivityTimeout so that you can have different players with different timeouts.

[knabar]

I have not dug into the code enough yet to know how to do that, but I'll take a look tomorrow.

[gkatsev]

Should be something like this.options()['inactivityTimeout']

[knabar]

Completely disabling the timeout (see #1213) would be trivial to add, perhaps by setting inactivityTimeout to undefined?

[knabar]

Just realized undefined is probably not practical since JSON cannot express it. Alternatives: null, -1, ...?

[gkatsev]

To disable it, just set it to 0.

[knabar]

If inactivityTimeout is set to anything less than 1, the controls will no longer hide.

[heff]

This looks great, thanks Andreas! Any chance you want to try and write a test for this? There's not an existing one so it might be a challenge, but let me know if you want to try.

[knabar]

@heff I added a test to check the different inactivityTimeout settings. Due to the nature of the tests, this adds about 8 seconds to the test execution time.

[gkatsev]

Looks like we should pull in sinon's fake timers for this test. Asyncornous tests are always flaky. sinon's fake timers allow you to control time in your tests which will make them run faster and more reliably.

[knabar]

@gkatsev I was not aware of that library, thanks!

[heff]

Is the html5mock part needed here?

[heff]

Tests look great, thanks!

[heff]

@gkatsev is zero the right setting here to disable it or should we use false? I'm worried there's a disconnect since setTimeout(fn, 0) still executes the function.

[knabar]

@heff removed unneeded html5Mock code

[heff]

Thanks Andreas!