JQL Navigator UI tweeks

There are a few little changes that should be made in the navigator:

• Remove the warning message about editing an invalid filter when on the advanced edit screen, you are already there, no need to see the message
• There is a link outside of the operations menu to Save - as a filter on the advanced and View navigator screens. This is duplicated by the the save in the operations, we don't need both, operations seems like the better one to keep.