Add option for connecting to HTML apps via XHR

[rigdern]

Some HTML-based app environments (e.g. Windows Web Apps) do not support cross-domain script inclusion but they do support cross-domain XHRs. This change adds a connection type ("HTML App (XHR)") for connecting to such app environments.

This depends on LightTable/LightTable#1507

[xjw000]

You can by value and id to. Controller it’s so easy Ajax or form