js/advanced: Restyle

Just style fixes and refactors.
js/advanced: Only submit unique values in form

This re-imagines the way in which the advanced search form
works. Instead of relying on hashing the differences between the form's
starting value and value at submission time, we instead supply a set of
default values which can be compared against the values at submission
time and used to determine whether the user has entered any meaningful
data.
js: Use advanced search form logic on all searches

This applies the same default value logic used in the advanced search
page to the main page and navbar search bars as well.
navbar.less: Add opacity transition on logo hover
Add the ability to preload search queries

This adds the ability to set the search term to be used by setting the
GET variable "q".
views/index: Don't fix the size of the logo

We need this to adjust flexibly for smaller devices.