Renamed towing module to listing.
Moved files to new directory.
Listing: Removed promoted sorting in SQL file.

This was causing promoted companies to be included from a different
city.
Listing: Fixed bugs and removed unneeded function.
Listing: Result template: Added company description.
Main script: Created contact form handling object.
Footer template: Added contact form.
Main style: Added selection text color.
Content style: Added style for promoted companies.
Footer style: Added style for contact form.
Language file: Changed query label.
Listing: Map template: Make visible only on desktop.
Added mobile style sheet.
Search form template: Make images and text optional on mobile.
Header template: Group logo and slogan with section tag.
Footer template: Hide advertisment for mobile on mobile.
Main style: Added color_element variable.
Header style: Use new color variable.
Footer style: Use selection text for icon color.