Duracloud: Stub out Space

refs #7133

Add empty Space, form, constants etc.
Duracloud: Add fields

refs #7133

Add fields to Duracloud Space. Update places to match: constant, forms,
migration, fixtures, test.
Duracloud: Add helpers

refs #7133

Add session with auth for use with all the other functions and
constructor for duraspace URL.
Duracloud: Add move from SS

refs #7133
Duracloud: Add move to SS

refs #7133
Duracloud: Move to SS supports globbing

refs #7133
Duracloud: Add browse

refs #7133
Duracloud: Add delete

refs #7133
Duracloud: Space path is optional

refs #7133
Duracloud: Browse works without leading /

refs #7133

Browse resources should only join with the Space/Location path if it does
not contain the Space/Location path already.  Some calls to browse contain
the full path, and others relative paths.  This should work for Spaces with
or without a leading / in the path.

Update directory browser JS in SS to handle paths that don't begin with / as
well.
Duracloud: Minor fixes

Don't display password, show the space path as <None> if it doesn't
exist.