find and prefer local desktop entries over system-wide desktop entries

[turtlewit]

Currently, local destop entries are ignored. This pull request adds $XDG_DATA_HOME to the destop entry search paths before $XDG_DATA_DIRS so that local destop entries are preferred over system-wide desktop entries. This is necessary for being able to override system-wide desktop entries for specific users (such as adding command line arguments or environment variables).

[Biont]

Thanks for your PR! Is it just me or is the ${XDG_CONFIG_HOME-${HOME}/.config}: completely wrong and should have been ${XDG_DATA_HOME-${HOME}/.local/share}: anyway? I think this could be a slip on my part, because what I wanted to do there is precisely what your PR is about. Could you verify that and maybe simply remove the ${XDG_CONFIG_HOME-${HOME}/.config}: as well?

[turtlewit]

Yep, it works without ${XDG_CONFIG_HOME}. I didn't remove it initially because I was unsure if there was a reason for it.

[Biont]

Great. Thanks!