More perf / cleanup

When putting together the HTML for the questions the code also
saves an array of the critical information. This array is now
used for all the functions that need to scan through questions
such as validate, defaults, reset, compute score, etc. Hopefully
this is faster than using the XML methods to extract the data
from the Data.xml object.

This also includes a change to automatically scroll to the first unanswered section when you click on the 'Unanswered questions" button above Submit. Works on IE 8, Chrome one Android tablet but not another (Toshiba).

Courtney