Refactor templates and css

Two big changes:
1) Template inheritance heirarchy changes
2) separate .css files for pages

1) Instead of having every template inherit from base.html, most
templates inherit from base_page.html which inherits from base. This
way, new pages that require a very flexible can accomplish this by
inheriting base.
Make vendors map use full page
rework vendor page controls column layout
Add a button for viewing the map page

We don't really want to keep the buttons, but while they are there, use
one to redirect to the most important feature of the site.
Fix lint and reorganize files
Make legend large to stop wrapping
Fix tests

DOM has changed
Update background color of sidebar
Merge pull request #356 from steventlamb/topic/fullscreen_vendor_page

Topic/fullscreen vendor page