New scaffolding macros.
Add documentation about solutions.
Address Geoff's comments.  Add after_AnswerDate_can_open and hardcopy_is_open options to make it possible to see all the part after the answer date, and all the openable parts in hardcopy.  Fix issues with viewing problems in library browser and problem detail page.  Add more CSS for those situations.  Open all sections in library browser.
Rewrap POD sections to remove trailing spaces, etc.
Merge pull request #153 from dpvc/feature-scaffold

New scaffolding macros.