items: accepts a array of objects which will be converted to a list of items by the spinner.
format: printf style formatting of each item - accepts named arguments.
Enhancements include:
- removal of all hardcoded styling for better theming capability
- visual test page made more appealing supporting browser zooming
- added utility functions to disable, enable and destroy ui.spinner
- up/down buttons listens to more mouse and keyboard events
- support for decimal and currency format
- ui.spinner now restricts input on keydown
- cleanup occurs when the input textbox loses focus. this seems to be a better approach for future scalability
