Style + Images

A bunch of updates:
* Added in a ton of image files! Because...
* The entries on the /codex page have styling.
* The login elements have (updated) styling to match everything else.
* The navbar has styling.
* The navbar is now pulled from a controller .js file, and the active
link is programmatically determined.

Non-style changes:
* Users with permission can now edit-in-place the codex entries.
Clicking save will commit them.
* Ditto for deleting entries.
* Fixed a weird bug with multi-line editable text divs. Long story
short, most don't allow newlines and the one that does ("text" div) does
some funky logic to make sure nothing screw up. This basically requires
trimming and updating the contents in the actual div any time an update
is committed; otherwise, when the update is picked up by the client, the
text in the div gets partially duplicated. Weirdness, ja.