Time Module missing in all branches except 2.0

[graw-prog]

The time.d module is missing from dsfml.system in all branches after 2.0 but still shows up in the documentation and tutorials.

[E.S. Quinn]

Thanks for pointing this out; We stopped supporting the dsfml.system.time module because it didn't offer benefits over Phobos' time module. We need to update the docs to reflect this.

[Jeremy DeHaan]

I wonder if might have been a bad idea to use Duration instead of Time. It seems to have caused confusion for at least a couple people and is likely to cause more confusion when the release goes live. dsfml.system.time doesn't offer any technical benefits over core.time, but it did have the benefit of being something people are used to.

I think the solution might be to revert to using dsfml.system.time again, but I keep going back and forth.