Add old camera and hawkcam pages and images and update for modern pelican

Turns out a lot of the camera links weren't working. This copies or ports a lot of functionality from the legacy website.

content/camera_feeds/.htaccess

+Header append Cache-Control "public"
+Header append Content-Description "File Transfer"
+Header append Content-Disposition "attachment"
+Header append Content-Type "application/xspf"
+Header append Content-Transfer-Encoding "binary"