Add a flash on checking the puzzle, to assure user it happened

This will also make the solved background fade in and out, which looks
nice.
Save puzzles and progress to indexedDB
Set solved status when opening a puzzle
Set title and completion of saved puzzles in list
Lists of in progress and completed puzzles
Move from indexedDB to localStorage

It doesn't look like the HTML5 apps will support the former.
Reset lists when returning from puzzle page

Also, only reset scrolling when switching sources.
Correct XHR response type is "text", not "string"

This caused problems on older WebKits.
Add prefixed CSS statements for older WebKits