Small fixes for alt sub editor integration

This commit applies some polish to the alt sub editor integration:

 - Prevent spinner from displaying continuously when adding a
   subscription
 - Hide the editor when changing subscriptions to limit confusion
   about what is loaded
 - Dynamically add a node to the tree view when adding a subscription
 - Make sure the 'View/Edit' tab gets populated when backing out of
   the stream or item view
 - Apply some default link styles

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>
Populate variable needed for batch item receive

In the integrated alt editor, we load the sub. grid differently, so
'sub' was not being populated.  Since we should only ever have one
subscription showing at a time (in this view), we can simply assign
the item to 'sub' as it is received.

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>