Turn a field into a local variable.
Remove some unnecessary semicolons.
API level 15 support: Use the Fragment classes from the support library.

Now that I have played with the latest API I am supporting approx 75% of devices
again. API level 15 is Ice Cream Sandwich:
See https://developer.android.com/about/dashboards/index.html
Remove an unnecessary semi-colon.
QuestionHelpFragment: Use MarginLayoutParamsCompat.

So we can set the margin on API level 16 too.
Make some methods private.
ItemActivity: Implement ItemFragment.Callbacks so that derived classes don't need to.
QuestionHelpActivity: Implement Callbacks.

Just to avoid the runtime check. QuestionHelpFragment derives
indirectly from ItemFragment but we don't really use it.