Allow site header to wrap

Preventing wrap causes the name of the site to extend past the right margin of the page on small screens
Stack footer content on small screens
Set background on the .network-nav class

The trickery with the background gradation doesn't work so well for small screens
Remove fixed width for .three class inside the .network-drawer on small screens
Adjustments for .get-symphony layout on small screens
Merge pull request #48 from bauhouse/integration

UI changes for responsive layout on small screens, closes #44, #45, #46 and #47
Add active state to network navigation
Merge pull request #50 from bauhouse/integration

Add active state to network navigation
Style margins for nested unordered lists
Reduce the top margin on #site h3 to 2.4rem