Fixed restore of qtype options, and error in unit test.

Dan,

The problem with restore was in the  `get_{old|new}_parentid('questionid');` calls.  `questionid` should be `question`.  I also changed the organization so that the question options are a direct child of the question itself, rather than an array of one options element.  This seemed cleaner to me.

The unit test problem seemed to be an undefined variable, but it's now failing on question answer comparison.  My guess is that the `correctanswershowbase` option isn't working correctly with decimal answers.

Cheers!