Duplicate post Tags UI for other taxonomies

[tellyworth]

This duplicates the Tags postbox UI (with the Add button and X to remove) for all non-hierarchical post taxonomies.

No doubt js experts will find it crude in spots but it works. I've left in two register_taxonomy() calls that I used for testing, lines 209 and 210 of edit-form-advanced.php. They're useful for testing this patch but should obviously be removed for production.

There's no real code for fetching or saving taxonomies other than post_tag. That should probably be included but requires some careful fitting with get_tags_to_edit() and friends so I've left it out for now. I added a quick filter as a crude fetch hook but it should probably be replaced with something more solid.

save and fetch code added

The new patch has some better code for saving and fetching. Note that, while wp_insert_post() still supports the tags_input item for compatibility, the new UI code now passes in $_POSTtax_input? instead.

The temporary test taxonomies are still there but moved to the bottom of taxonomy.php.

fix conflicts and diff against 7521

fix css, l10n, autosave, enter keypress

Would love if the get and set of post terms dealt with IDs instead of names since we're in the code.

Updated patch applies to trunk

Same patch as before, but applies cleanly to r7641.

patch against r8339 plus improvements

Feature freeze.. move to 2.8 for now.

post taxonomies ui patched against r10210

Instead of passing a taxonomy arg to a tag function, we should just use the generic term function. That tag functions are convenience wrappers but if we're passing a taxonomy to them they are fairly pointless.

Not sure what the show_message() call is about. Seems it should be removed.

Lose show_message(). Fix notices. Use generic terms funcs instead of passing tax to tag funcs.

(In [10222]) Allow muliple tag-like taxonomies in the post editor. see #6387