Maps functioning, half-assed nav

Next and previous buttons pull correct content, including map pins and
centering. It is a tacked-together mess back there, but it's working,
so whatever. Adding several plugins for native nav and maps in next
commit.
PK Native Controls nav bar working. Rudimentary TOC – method works, not styled or filled yet. Committing before I figure out home and map views – either in or out of this WebView.
Native nav, rudimentary TOC

Probably a duplicate of the other one. Git's being weird. PK Native
Controls functioning, a rudimentary TOC (functional, but not styled or
full).