Log Message:
ruby-gnome: Update to 3.3.8, and rename package names to match gems.

Also reorganize several dependencies in Makefile and buildlink3.mk.
See the following post for details:
 https://mail-index.netbsd.org/pkgsrc-users/2019/09/07/msg029327.html
 https://mail-index.netbsd.org/pkgsrc-users/2019/09/13/msg029356.html

Upstream changes (from NEWS):

== Ruby-GNOME 3.3.8: 2019-09-10

This is a partially GLib 2.62.0 support release.

=== Changes

==== All

  * Improvements

    * Changed our project name to Ruby-GNOME from Ruby-GNOME2.
      [GitHub#1277][Suggested by kojix2]
      [GitHub#1291][Patch by kojix2]

    * Stopped to release (({.tar.gz})) because they are no longer
      used.

==== Ruby/GLib2

  * Improvements

    * (({GLib.convert})): Changed to set correct encoding.

    * (({GLib::FILENAME_ENCODING})): Added.

    * Changed to use the same enum object for the same enum value.

    * (({GLib::Enum.find})): Added.

    * (({GLib::Bytes#initialize})): Changed to reuse (({String})) data
      even if the given (({String})) isn't frozen.

    * (({GLib::Bytes.try_convert})): Added.

    * (({GLib::Enum.try_convert})): Added.

    * (({GLib::Flags.try_convert})): Added.

    * (({GLib::Type.try_convert})): Added.

    * (({GLib::MkEnums.create})): Added support for flags to enum
      definition.
      [GitHub#1295][Patch by Mamoru TASAKA]

==== Ruby/GIO2

  * Fixes

    * Renamed to (({Gio::Icon#hash})) from (({Gio::Icon.hash})).
      [GitHub#1293][Reported by Erik Czumadewski]

==== Ruby/GObjectIntrospection

  * Improvements

    * Introduced (({try_convert})) protocol.

==== Ruby/CairoGObject

  * Improvements

    * (({Cairo::Context.try_convert})): Added.

    * (({Cairo::Device.try_convert})): Added.

    * (({Cairo::Pattern.try_convert})): Added.

    * (({Cairo::Surface.try_convert})): Added.

    * (({Cairo::ScaledFont.try_convert})): Added.

    * (({Cairo::FontFace.try_convert})): Added.

    * (({Cairo::FontOptions.try_convert})): Added.

    * (({Cairo::Region.try_convert})): Added.

=== Thanks

  * kojix2

  * Erik Czumadewski

  * Mamoru TASAKA