Remove the label/value hack on the "Set Detail" page.

[drgrice1]

This make those fields that have the special word values (such as "Unlimited", "Set Default", etc.) be numeric inputs again. However, those special word values are separated into a select. So now there is a select and a number input. The select gives the option to choose one of those word values, and it also has a numeric option (labeled appropriately for the field). When that numeric option is selected then the value in the number input is used.

With this change the old "undoLabels" hack is no longer needed. That is the hack that switched the word values back to the numeric values server side. The select options already have the correct value. The select also has a special "numeric" value that signals that the number in the number input is to be used instead.

This is an approach to replace the previous number input approach implemented in #2820 and reverted in #2823. Unfortunately that approach had some issues that could not be relegated purely with a number input.

I also noticed that there was an issue when the $test{maxProblemsPerPage} variable is set to 1. In that case the problems_per_page setting would not be shown when editing the global set or editing a set for several users. However, when editing the set for a single user the setting would be shown, although it still couldn't be edited. It doesn't make any sense to show an option that can't be edited for the set as a whole, and isn't even shown in that case, when editing for a single user. In fixing that issue I noticed that the override "none" setting in the FIELD_PROPERTIES hash is rather messed up. See the comment I added on line 84 of the ProblemSetDetail.pm file. That setting is no longer used since I removed the attempted, last_answer, num_correct, and num_incorrect fields from the hash that were nonsensically included in that hash with the override "none" and type "hidden" values, which basically meant that those fields were ignored everywhere.

Note the FIELD_PROPERTIES_GWQUIZ constant was also remove because it was not used in actuality. The only field in that hash was the max_attempts field, but since it is no included in the GATEWAY_PROBLEM_FIELD_ORDER array that hash key was never accessed.