[gtkada] Request to publish repository again

[John Marino]

I understand from Emmanuel Briot that Adacore repositories have been
converted from Subversion to Git.  Actually, we were talking about GPS
specifically, but looking at the stale state of GtkAda repository, I'd
have to guess that all the repositories have been converted.

I know it's not a priority, but it would be nice to get gtkada repo
available publicly.  Gtkada for GPS 6 does _not_ build with the upcoming
FSF GNAT 5:

I- -gnatA
/wrkdirs/x11-toolkits/gtkada3/work/gtkada-3.8.3.1/src/gtkada-canvas_view-views.adb
gtkada-canvas_view.ads:373:04: interface function "Is_Link" must be abstract
gtkada-canvas_view.ads:448:04: interface function "Edit_Widget" must be
abstract
gtkada-canvas_view.ads:464:04: interface function "Parent" must be abstract
gtkada-canvas_view.ads:477:04: interface function "Inner_Most_Item" must
be abstract
gtkada-canvas_view.ads:510:04: interface function "Is_Invisible" must be
abstract
gnatmake:
"/wrkdirs/x11-toolkits/gtkada3/work/gtkada-3.8.3.1/src/gtkada-canvas_view-views.adb"
compilation error

I'd rather cherry pick the fix from the repo because I'm 95% sure this
has probably already been fixed.

For my 2 cents, a github mirror would be just dandy if suits Gtkada folks.

Thanks,
John