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.
Merge pull request #54 from rachelbaker/issue-51

Added conditional to verify the $user object is set in prepare_author method.

Fixes #51
Merge pull request #49 from rachelbaker/multisite

Updated plugin activation and deactivation functions to be multisite compatible.

See #48
Merge pull request #65 from tierra/ticket-3-unit-tests

Added unit testing skeleton with mostly stubbed server tests.
Test all versions of PHP, with WP trunk
Add documentation on testing/developing
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
Change function semiCamelCase names to underscore_case on lib/
Change function semiCamelCase names to underscore_case on docs/
Change function semiCamelCase names to underscore_case on plugin files.
Use name of plugin on deprecated notice.