simplifying and adding categories

Conflicts:
	system/expressionengine/third_party/json/pi.json.php
fixed bug where dates were not numeric
added show_categories to json:entries
added search tag
added jsonp support
refined global parameters

Conflicts:
	system/expressionengine/third_party/json/pi.json.php
return entry_id as an integer

Conflicts:
	system/expressionengine/third_party/json/pi.json.php
Custom date formats parameter

Conflicts:
	system/expressionengine/third_party/json/pi.json.php
added camel_case global param
fixed typo bug in search
refined some code

Conflicts:
	README.markdown
	system/expressionengine/third_party/json/pi.json.php
fixed some matrix bugs
use json_encode if available
removed force object in json_encode
only get fields from current site
Use INTs where applicable
Refactor Matrix for clarity
Add support for new Relationships
Add Playa support
Add Grid support
Update docs
Add Assets support
refactor Json_Template class
Add some docs on Assets support