Fix the editing of vocabulary terms (#460206, #172797, #347568).
With this commit, vocabularies are actually working, even the free tagging
ones. Note though that this may have broken Organic Group support (though
I have the nagging suspicion that was broken anyway, see #586160).
The current implementation honors the selection of taxonomies within the
Taxonomy:All Terms views field. Only selected vocabulary will be editable.
Of course, if you select vocabularies that are not in the node edit form
(because they are not attached to this node type) you will not be able to
edit them anyway.
Only if more than one vocabulary is editable the name of the vocabulary is
rendered.