Droplets theme

[willgearty]

This is the start of a new theme, based largely on bigpicture, called "droplets", named after the dropdown nav menus. It includes the following improvements:

• Fixed navbar that stays at the top of the screen even when scrolling
• Dropdown navigation menus
• Admin toolbar, morph details, and login info/form integrated into navbar
• Supports glyphicons for dropdown options
• Increases width of main content to full width of screen
• Responsive to device screen size (including the navbar turning into a collapsed vertical menu)

Still to be done:

• Clean up admin toolbar dropdown styles?
• Fix up theme tests?
• Navbar dropdown headers don't support links since clicking them opens the dropdown (we could just modify the theme editor to be clear about this or figure out a way to allow for actual links)
• Integrate bootstrap variables? (@kkbrum is more familiar with this than I am)
• Make and integrate optional variables to alter navbar appearance?
• Check how lots of pages look with full screen width
• Check compatibility of responsive.css on other themes

While making this theme responsive, I discovered that all we needed to do to make other themes responsive was to compile an additional bootstrap file. Since this is now included in theme_compiled.css, I've removed the line pulling bootstrap from the CDN which apparently wasn't doing anything.