Attach click event to the #wsu-actions-tab container

This avoids the overhead of attaching multiple click events for each page load. Instead, we look at the overall click event on wsu-actions-tab and grab the element it was intended for.
Cache the wsu-actions selector for use throughout

Rather than using jQuery to find DOM information for the selector each time, we can cache it once and reuse it.
Cache the spine selector for repeat use throughout
Consistent use of tabs, spacing throughout spine.js
Cache main element for use on window resize

This avoids jQuery going out and grabbing the entire main element on each instance.
Move click capture for wsu-print-tab into wsu-actions-tabs group

Reduces the number of click events added on the page
Additional selector caching, use of find() for descendants
Fix missing indents
Comment out assignment of offset in mainheight()

This variable does not appear to be used anywhere after assignment and the jQuery lookup is pretty expensive to do repeatedly.
Fix menu behavior broken in 576478f5a0d0

We needed to be explicit about the li
Merge pull request #13 from washingtonstateuniversity/review

[PR] General improvements, including selector caching and click event reduction