Added support for pkgng multiple repositories.

Currently checking if pkgng >= 1.1.4, as specified in
https://wiki.freebsd.org/pkgng . I guess that's when using PKGSITE was
deprecated.
Changed old variable names that referred to pkgin.
Added support for package annotations.
Merge pull request #6405 from fabianfreyer/devel

Add support for new pkgng repository format and annotations