[gedit-list] Import and Export Gedit Snippets

[<archil imnadze ge>]

Hi. I make modifications in built-in snippets and also add new ones. The
two problems that arise here are the following: one that exporting only
modified snippets is impossible, two when importing overwriting existing
snippets is impossible. If there is a way of doing these and I'm missing
something, please, let me know. Otherwise I'd suggest for a new feature
of selective importing and exporting. It will solve the problem and
improve usability of snippets plugin. Thanks!