Marker removal?

[gzotti]

Suggestion from SF forum https://sourceforge.net/p/stellarium/discussion/278769/thread/b2a4b59d/#1be4

Sometimes a user will accidentally place a bad custom marker, and the only way to get rid of a marker is to delete them all. It would also be nice if custom markers had their own little panel inside a configuration window or something like that (where you can add/delete/modify them). The ability to name them would also be great; users will be able to use them for planning where to center their image and perhaps just for marking down interesting objects.

GZ: We could test for vicinity when shift-clicking on the screen and remove some marker when e.g. shift-alt-clicked close enough (FOV-dependent or just pixel distance). I think extra panel or such for renaming/editing would be nice for real user data collections which may need to be stored/reloaded, not for these quick-hack markers. Maybe combine with Bookmarks? As always, whoever really needs this feature will best be able to tweak the code.