Link collection filtering docs to URL formatting guide

As noted in the compatibility document, URLs do not provide any standard
convention for passing query parameters as an array. Linking the collection
filtering guide to the article explaining the URL array syntax used in this
API will reduce confusion for new users.
Don't check for IXR_Error
Remove IXR includes
Merge pull request #74 from kadamwhite/cross-link-docs

Link collection filtering docs to URL formatting guide
Remove hardcoded /pages references
Merge pull request #78 from WP-API/replace-hardcoded-pages-references

Remove hardcoded /pages references. Fixes #28.
Workaround for createFromFormat on PHP > 5.2
Merge pull request #79 from osiux/issue-52

Workaround for createFromFormat on PHP > 5.2

Fixes #52.
Change to WP official git mirror
Just copy the files instead of cloning the repo again (this way it even works on branches tests, I think)
Merge pull request #80 from osiux/fix-travis-integration

Fix travis integration
#85 - added timezone parameter to WP_JSON_DateTime::createFromFormat() in parse_date method.
Provide default timezone fallback in WP_JSON_DateTime::createFromFormat().
Added class comment and code formatting fixes to WP_JSON_DateTime class.
WP_JSON_CustomPostType __construct() requires a param of type WP_JSON_ResponseHandler. This needs to be documented. It's not clear how to write getPost, editPost, getPosts, and newPost methods mentioned in the MyPlugin_API_MyType class: I added a sentence explaining where you could start with these.
Merge pull request #88 from tlovett1/master
Merge pull request #87 from rachelbaker/issue-85

#85 - added timezone parameter to WP_JSON_DateTime::createFromFormat()
Move from wp-json.php/ to wp-json/
Use `wp-json/` in documentation
Merge pull request #96 from WP-API/drop-php-suffix

Drop PHP suffix from URLs