Update to Sandbox Panel

The panel itself has been updated with subcategories and additional options.  The "air regulator" option was removed because what even does that mean.  The Suit Up option has been fixed, and should work properly now.  Additional items include an all-access ID, RCD, flashlight, light replacer, plasteel, cable, floorbot, medbot, gas mask, and emergency air tank.

The hrefs var was moved out of global scope because that's a terrible place for something so generically named.

The Spawn Item and Spawn Canister dialogs now use a browser window instead of a pick list.  This window is cached per user.

Sandbox's Spawn Airlock option gets a new interface.  It allows you to pick the accesses of the new airlock, as well as its paintjob, name, glass inserts where appropriate, and an option to make the access list "require one" instead of "require all."  It adds an airlock frame which can be repositioned; attack-hand-ing the airlock frame (if it has the airlock builder datum attached) will now open the window.

An administrative option has been added to the sandbox panel, which is configurable through game_options.txt.  Because the item spawning uses a persistent browser window, it is susceptible to spamming.  The added option forces the window closed after each item is spawned.  This only affects the item and canister selection windows, and not the whole sandbox panel.