UI Updates: Arizona Linen Theme + Logo Click Change

Added new theme per spec from Lori. Changed logo click to render home
page overlay instead of go to '/' URL. Changed View Tours panel to
display a "here is where you can find the Big History" type of message
and link if the current collection is not the Big History collection.
UI Updates: Publish Wording Change

Changed checkbox label and tooltip on the Customize Collection panel per
https://trello.com/c/B1wg2bkP/188-publicly-searchable-option-rewording