Support for data-action and data-href in callRemote

[mjonuschat]

Make callRemote() more universal by supporting "data-action" and "data-href" in addition to the "href" and "action" attributes.

Reason for this:

1. use different links based on javascript support in browser
2. make it possible to trigger callRemote() from elements not supporting "action" or "href" attributes

A possible implementation is in this commit: 3119c79a9b515f17356542e8bc56779ac5580141

[stevestmartin]

There was a previous implementation where this functionality existed, however it was discussed that it was not needed. The driver is not meant to server as a complete library only to provide a default implementation for the view helpers.

Firing off an ajax call on elements that are not links or forms is relatively easy with jQuery

[hiroshi]

But, how about input[data-remote]? callRemote try to get url from action or href from the input. At least, callRemote should try to get url from form[action] of the input.