Patch: Add avidemux

[Andreas Enge]

Hello,

this one was not pretty...

The command line program avidemux3_cli does not work from the bash script
I am using.
avidemux3_gtk opens a little window "Glade - Cannot load glade file",
and prints the following error messages (among others):
Trying 
:</gnu/store/mp8fhmf27ib6i8wacd207k8jfcn0wdkp-avidemux-2.6.8/lib64/ADM_glade//main/gtk2_build.gtkBuilder>
                                                                          
[GtkBuilder] Invalid property: GtkGrid.n_columns on line 549                    
             
Trying 
:</tmp/nix-build-avidemux-2.6.8.drv-2/avidemux_2.6.8/avidemux/gtk/ADM_userInterfaces/ADM_toolkit_gtk/../glade/main/gtk2_build.gtkBuilder>
                                          
[GtkBuilder] Failed to open file 
'/tmp/nix-build-avidemux-2.6.8.drv-2/avidemux_2.6.8/avidemux/gtk/ADM_userInterfaces/ADM_toolkit_gtk/../glade/main/gtk2_build.gtkBuilder':
 No such file or directory                                                      
                             
Trying :<glade/main/gtk2_build.gtkBuilder>                                      
             
[GtkBuilder] Failed to open file 'glade/main/gtk2_build.gtkBuilder': No such 
file or director
So it looks like the build directory is also coded into the binary.

Fortunately, avidemux3_qt4 works. So I would suggest to submit it as it is,
as I am not motivated to debug the gtk version, unless someone feels like it.

Andreas