Template should use correct copyright year

[Toxaris]

Some templates put "copyright 2015" snippets in LICENSE or *.cabal files.

Minimal fix: Should be changed to "2016".
Better fix: Should be computed based on system date at call time of stack new.

[eriknstevenson]

Thanks! Just created #29.

Having the date be calculated by stack new would be a nice feature that should be trivial to add. Recommend creating the issue in the stack repository.

[mgsloan]

Good point! I've merged that PR, so now templates can use {{year}}

Note that we should test what happens when {{something-not-defined}} is used with templates. It wouldn't be good to break old stack versions.

[eriknstevenson]

Note that we should test what happens when {{something-not-defined}} is used with templates. It wouldn't be good to break old stack versions.

Mustache behaves as follows when a tag is undefined:

template	output
{{undefined}}
{{undefined}}{{^undefined}}default value{{/undefined}}	default value

[mgsloan]

I didn't realize that, nice feature!