implement MoveFileOrDirectoryToTrash on Linux

[eyelash]

I tested (on Ubuntu 13.10):

• deleting files
• deleting directories

both worked

[timburgess]

I like the idea of using g_file_trash(). I've submitted some code for the same function in another PR but it's much more lower level C code and will only work with the Ubuntu trash. Using g_file_trash() there is more likely a chance that it will work with trash on other distros. If someone could test on a non-Ubuntu flavor that would be great.

[jasonsanjose]

Linking to #284. Reviewing both.

[jasonsanjose]

Looks good and tested on Ubuntu 13 64-bit after merging with master locally.

If I understand my libraries right...GIO is part of GLib. Since we require this in our debian package control file as a dependency, and presumably will require it for other distributions (Fedora is probably next), this should work across distributions right?

@eyelash it doesn't matter much currently since we don't have support for other distros yet. If you happen to know if this works on Fedora, just leave a note here.

Merging.

[eyelash]

GTK+ depends on GLib so every distribution that has GTK+ also has GLib. I don't use fedora but I'm quite sure this solution works for most of the distributions.

[jasonsanjose]

Great. Thanks @eyelash. Also, thanks for signing the CLA.