refactor getRequest. Move to TingClientRequest.php
alter check to empty()
dont try a http request if url is empty
add exception if XSD is NULL, and remove duplicate system_settings_form code
Merge branch 'feature/1307-validate_xsd' into develop
use method system_settings_form to set submit array and form_error check
tagging version 7.x-2.20
Merge branch 'release/7.x-2.20'