Update header and footer to match orangelight

[hackartisan]

resolves #287
resolves #378

[hackartisan]

The site title only displays on child pages, to avoid redundancy with the front page masthead

[coveralls]

Coverage remained the same at 100.0% when pulling 3fa4cff on issue/287-update-header into 5deadf1 on master.

[jrgriffiniii]

I'm getting some issues when the viewport is reduced to 320px on https://dpul-staging.princeton.edu/cotsen within the staging environment using Firefox Quantum release 61.0:

Please disregard if this is out of scope.

Otherwise on the specified release of Firefox and Google Chrome 67.0.3396.99, this is perfectly responsive 👍

[jrgriffiniii]

Testing on Edge 17 using BrowserStack also demonstrated that this is satisfactory.

[hackartisan]

thank you for the thorough testing!