fixes #3600 Replace / in bookmark name with _

[stbenjam]

Fix for #3600. When a user creates a bookmark name that has a "/", it breaks the bookmarks page. The user would then have to delete the entry manually from the database. This fixes that be replacing "/" in a bookmark name with "_".

Not sure if you'd prefer to error out and tell the user not to use "/"'s instead. Maybe that's the better solution.

[domcleal]

Ah, thanks for the PR @stbenjam. We're going to fix this via #988 instead which will avoid using / in URL resource identifiers, so you'll still be permitted to include them in the bookmark names.