Alec Theriault authored Mar 26, 2018 and Alex Biehl committed Mar 27, 2018

* Metadoc stores a package name

This means that '@since' annotations can be package aware.

* Get the package name the right way

This should extract the package name for `@since` annotations the
right way. I had to move `modulePackageInfo` around to do this and,
in the process, I took the liberty to update it.

Since it appears that finding the package name is something that can
fail, I added a warning for this case.

* Silence warnings

* Hide package for local 'since' annotations

As discussed, this is still the usual case (and we should avoid being
noisy for it).

Although this commit is large, it is basically only about threading a
'Maybe Package' from 'Haddock.render' all the way to
'Haddock.Backends.Xhtml.DocMarkup.renderMeta'.

* Bump binary interface version

* Add a '--since-qual' option

This controls when to qualify since annotations with the package they
come from. The default is always, but I've left an 'external' variant
where only those annotations coming from outside of the current
package are qualified.

* Make ParserSpec work

* Make Fixtures work

* Use package name even if package version is not available

The @since stuff needs only the package name passed in, so it
makes sense to not be forced to pass in a version too.