Specifies the position of the button icon relative to the button text in any buttons in the Navbar.
Default value
Blank - uses the jQuery Mobile default position of 'Left'.
Valid values
Left - position the icon to the left of the button text.
Right - position the icon to the right of the button text.
Top - position the icon above the button text.
Bottom - position the icon below the button text.
No Text - draw the button with no text (icon only).