Shields are now an stl container.  Reimplemented get highest shield
in terms of the STL in-place since it was only used once and got rid
of the shieldlist class as well.  In order to simplify memory management
replaces the Shield * with shared_ptr<Shield> which provides a smart
ref-counted pointer, so that just clearing (or erasing) an element from
the container will delete the allocated memory.

Removed all uses of AList from the quests system (quests and rewards).
Retained the QuestList class since it had a number of useful functions
and reworked it using an internal std::vector.  Renamed all the
member functions to follow intended style going forward.

This had mostly been done, so this was just cleaning up a leftover
place or two where it hadn't been fully removed.  Also renamed the
production class's functions using the new style.

This has been partially done previously, this was just cleaning up
some leftover turds.  Renamed Market class functions to use new
style of naming.  Make the enum type for the market into a named
enum.