Improve the class comments of Controller_Rest_Data and Controller_Rest_Item.
Move Hook_Rest_Items --> Controller_Rest_Items

--HG--
rename : modules/gallery/classes/Hook/Rest/Items.php => modules/gallery/classes/Controller/Rest/Items.php
rename : modules/gallery/classes/Gallery/Hook/Rest/Items.php => modules/gallery/classes/Gallery/Controller/Rest/Items.php
Fix class declarations for just-renamed classes.
Revise Controller_Rest_Item: only use weights as member keys for scope=direct.
Make Controller_Rest::before() do a little more parameter processing for us.
Fix bug in Controller_Rest::action_get().
Rewrite Controller_Rest_Items.
Add Controller_Rest_Items::post_entity().
Move Hook_Rest_Tree --> Controller_Rest_Tree.

--HG--
rename : modules/gallery/classes/Hook/Rest/Tree.php => modules/gallery/classes/Controller/Rest/Tree.php
rename : modules/gallery/classes/Gallery/Hook/Rest/Tree.php => modules/gallery/classes/Gallery/Controller/Rest/Tree.php
Fix class declarations for just-renamed classes.
Remove "fields" parameter implementation from Rest class - only for tree.
Rewrite Controller_Rest_Tree.
Revise comments in Controller_Rest_Items.
Merge pull request #399 from shadlaws/fixes_20130612

Fixes 20130612