Revert "Show list of tags in PlacesView"

This reverts commit 2ae8a0c374cd175380945fc7fae1a38957272435.

It's a great feature, but not quite ready for prime time yet. For example, tag
ordering needs to be deterministic, and user-created tags should disappear
when they're no longer in use.

CCMAIL: nicolas.fella@gmx.de