Destroy method

A little bit of a markup clean up omnibus, too... i wanted to get this in here before the codebase changes much.

NOTES ON DESTROY EDIT:
- Add destroy method to all controls, returns "original" markup with updated input values for non-data-sourced controls, removes a few events and all the control's jQuery.
- Add destroy and append buttons to index.html 
- Only remove events attached to window if they are specific to control instance (may need unique ID)
- If component (such as scheduler): store markup inputs, then destroy call child controls, then remove rest of markup
- Allow inputs to be declarative, don't destroy input value by default
- Update selectlist to be declarative with hidden input value and current selection (data-attribute)
- Loader method 'prev' > 'previous' for wizard consistency
- Make example control IDs consistent with "My" prefix
- index.html: Add sections, inputs > buttons
- index.js move datasource-needing controls into an init function to call after destroy 
- Ignored destroy auto-flip, since there is no variable instance/constructor

At time of PR, DATEPICKER is still destructive of input value by default and hopefully not be so when datepicker is updated.