Clean up JS formatting

Change indentation to be consistently spaces, not mixed tabs and spaces.
Fix JSHint warnings as much as possible.
Improve navigation

Move navigation to top of page. Ensure this is always available, including
after results have been given back to the user.
Clean up CSS

Consistent indentation throughout. Replace tabs with spaces.
Enhance results formatting

Adjust the results formatting to make it easier to read. Include the class
or room in a new page heading, so the user is not guessing what it was
they are seeing results for.
Fix lookup error

Only perform an AJAX lookup of an offering for an offering ID, not all IDs
that are found in the XML tree (eg. ignore the semester ID).