devel/gps: Upgrade to 2016 release (plus 2 dependencies)

x11-toolkits/gtkada3: Upgrade version 3.8.3.2 => 3.14.2
devel/gnatcoll: Upgrade version 2015 => 2016
devel/gps: Upgrade version 6.1.1.0 => 2016

This upgrade appears to work flawlessly on DragonFly, but
on FreeBSD the PR list below regarding navigation to code
error is unfortunately still valid.

PR: 202317