Changed the behavior of "always_show_hint" and "always_show_solution" permission settings so that they do not take effect when generating a hardcopy.

Unintended Side Effect:  The only way that hints were shown in hardcopies was via the "always_show_hint" setting.  This change makes hints unavailable in hardcopy for everybody.
Fixed 2703 in the manner suggested by Mike.  I commented out character escaping in "problemPreserveAnswer.pl" because it is done earlier now.
Implemented Davide's suggestions.
Removed problemPreserveAnswers from anywhere I could find it.
Merge pull request #51 from goehle/bugfixes

Merging your fixes.  (As a practice, I'd like to see a separate pull for each bug, rather than mixing them together.  That makes it clearer which changes are for which bug, and makes it easier to back out of changes if there ends up being a problem.  Here, the fixes for dollar signs are mixed in with the fixes for the printing of hints.)