Added support for jQuery Mobile 1.4 button styles.

In jQM 1.4 they changed the button classes from `ui-btn-up-*` to `ui-btn-*`.  Rather than deal with parsing the jQM version, I simply added the `ui-btn-*` style in modButton.  

This fix gets action buttons looking right in jQuery Mobile 1.4.  It does not seem to effect older jQM versions, and your demo still styles correctly.

Note: I didn't generate the `all` .js files because I was having difficulty producing the minified version that corresponded to how you've been doing it.