Fixes a few persistent style issues

[meiqimichelle]

• Removes words from social media in navbar because tl;dr, and then it displays better on smaller screen sizes, too
• Changes 'calendar' links on nav and homepage from a subpage with an iframed google cal, to our meetup site
• Changes number of projects displayed on homepage from 2 to 3 -- we have more projects now, yay! and three looks nicer.
• Provides basic responsive code for splash and 'Code for Tucson' words
• Fixes visual bug in splash where a white bar showed up a certain screen sizes
• Adds spacing between subpage title and splash/content

[dmsnell]

Looks good although I would recommend opening the calendar in a new window so as not to disrupt the normal navigation. You can ignore me on this too :wink:

After that, :ship: it!