Update docblocks for all classes
Minor fixes to groups and attributes

* Remove attribute data from groups test posts
* Change test group labels - for more sanity and reuse in docs
* Add test to check all attribute values are saved in POST attributes
* Add test to check all attribute values are saved
  in POST forms/:form_id/groups/:group_id/attribute
* Add test to check all attribute values are saved in POST /forms
* Fix forms, attributes, and group attributes API calls to save all values
Minor Posts fixes

* Whitespace fixes
* Fix handling of form_id in posts api: no PHP error if missing
* Only check parent exists if not empty
Building Tags API #14

* Setup tag validation and filters
* Add Tag_Model::for_api()
* Add unique index to tags table
* Add basic Tags controller
* Add tags feature test
* Add tags fixtures
Add tag search function #14

Allow search by type, parent, tag and tag w/wildcard (q)
Merge commit '61728e0'
Clean up docblock in database template
Build /posts/:post_id/updates/:id API endpoint #26

* Rename streams to updates
* Add tests
* Better error message for missing parent post
Add build status image to readme
Better attribute not reserved check
Add not about Testing to readme
Tags: Better handling of 'parent' field

* Allow parent id, parent slug, or parent array
Merge branch 'master' of git://github.com/ushahidi/Lamu
Fix stray : in validation error messages

: was missing from replacement :errors token
Fix stray : in validation error messages

: was missing from replacement :errors token
Merge branch 'master' into api-tags-14
Posts and Post_* improvements

* Share code for unpacking 'form' property
* Make all Post_* models extend Post_Value
  * Use this to handle rules for post_id and form_attribute_id
  * Add check that foreign keys exists
* Add central ORM class to define fk_exists() function
Use general fk_exists check for form check in Group model
Make Tags only unique within each type and parent group
Posts: check for tags by id and slug, rather than name.