Refactore how dialogs are populated with values so that the values will be present by the time the user sees the dialog, rather than filling in a moment after the dialog stops.
Added support for folder metadata display and editing.  The metadata widget is more agnostic, and I've renamed the internal classes from item-metadata to widget-metadata.  The metadata functionality has been moved into a general model mixin rather than just in the item model.
One of the metadata tests was supposed to exercise preventing renaming an existing key to the name of another existing key.  This wasn't doing that.
Added web client folder testing.  Fixed an issue where if an item had metadata with a unicode key, you could not edit the item's name or description.  Fixed some css.  Explicitly made foldercreate and folderedit as different dialog paths to match what is done with items.  Made testing metadata more general so that it could be reused for folders.
When we merge the assetstore-edit branch with this one, we need to add some waits in the test for dialogs to come and go.
Removed an unused variable.
Merge pull request #424 from girder/folder-metadata

Folder metadata