Update home.html

Added class and div structure for new gray banner around search field
Update home.html

Adjustments to search box divs and added class for out container
Update home.html

Removing form changes
Update index.php

Added gray banner and 'search all' text to search field
Update index.php

Added class to form fields div
Merge pull request #181 from gwu-libraries/t178-gray-search-header

T178 gray search header