Another big release.

• Critical-rendering path optimisation. We now inline critical path CSS
• Both Ember's vendor bundle and app JS are now loaded with defer
• We now use the assets directory for all images, fixing some deployment issues

Cable:

• WebPageTest: http://www.webpagetest.org/result/160427_2Y_17SE/
• 1st 1086 speed index, 476 repeat

3G:

• WebPageTest: http://www.webpagetest.org/result/160427_MH_1811/
• 1st: 2015 speed index, 603