[gcmd-usr] dependency package naming

[bendov]

Just as an FYI & maybe I'll get some general helpful tips for the future.

Gnome-commander https://gcmd.github.io/2019/05/30/gcmd-ubuntu-deb.html
checking if libraries needed to install / dependencies are present:

gtk+2.0 - found no such pkg listed in Mint Synaptic or Software Manager.

https://launchpad.net/ubuntu/+search?text=gtk%2B2.0 - shows  "Your
search for “gtk+2.0” did not return any results."

I had to search following link to find the :  "You can search again
including package descriptions."
https://launchpad.net/ubuntu/+search?search_type=source&text=gtk%2B2.0
Then, launchpad lists a package general HEADING "GTK+2.0", but not as a
specific download pkg name.  It's part of the pkg name on Launchpad (if
incl. pkg descriptions), but isn't listed that way at all in Mint repos
or as installed pkgs.

So, it's not that easy to find it for Mint, even when the Ubuntu
Official repo (base) xenial http://archive.ubuntu.com/ubuntu is an
official repo in Mint Synaptic or Software Manager.

Launchpad site shows for ubuntu 16.04 a download:
gtk+2.0_2.24.30-1ubuntu1.16.04.2.debian.tar.xz, but you won't find a
name "GTK+2.0" in Mint repos *or* by checking installed packages (even
though all necessary gtk2.0 libs are already installed & updated).  In
Mint, to check if gtk+2.0 is installed & version, need to enter
command:  $ dpkg -s libgtk2.0-0.  This is how it's listed in Mint repos
or if searching the Mint installation.