Fix #702, adding plugin context to asyncValidators

Fix #702, adding plugin context to asyncValidators

Remove commented/replaced line

Merge branch 'master' of github.com:cautionbug/Parsley.js

Conflicts:
	src/extra/plugin/remote.js

Remove commented/replaced line
* Fix issue #702 to give ParsleyField context to asyncValidator callbacks
* Updated test.js to pass ParsleyExtend to remote()
* Added test to remote.js to test `this` context within asyncValidator callback
* Updated documentation about `data-parsley-remote-validator` to explain `this` context, and updated code example.
Merge branch 'master' of github.com:cautionbug/Parsley.js