#591 Add multiple separator support

[Robert]

It'd be nice to have multiple separator support, e.g. "GO", "/" and ";".

Separators should be checkable / uncheckable in settings to indicate they are active or not.

Very useful w'd be the option to set those alias (database) specific and not only globally in new session properties. I like to use specific separators for specific databases but not to change each time for a new session created or globally but have it bound to the alias (database).