Menu widths and menu button parameterized

### Modifications for the menu width
I extended the $.mobile object to add a couple of parameters for the menu's width & min-width. They default to 25% and 250px, respectively, as they were hardcoded in the master branch. The project I'm working on requires they be 27% and 270px, and we don't want to modify the delivered code.

### Modifications for the portrait mode popover menu and button.
* Added parameter to set which side of the screen the popover menu button appears (defaults to "left").
* Changed selector that sets the data-role="page" CSS to min-height:100% (old selector would return null when the page opens).
* Unbound the resetPageHeight call in popover (did not appear to have any adverse effects).