Build remaining example graphs

[kylegifford]

• regions - depends on Implement c3-data-region #3
• simple XY - depends on Implement c3-data-x #1, Implement c3-[x,y,z]-axis and c3-tick #2
• multiple XY - depends on Implement c3-data-x #1, Implement c3-[x,y,z]-axis and c3-tick #2
• scatter - depends on Implement c3-data-x #1, Implement c3-[x,y,z]-axis and c3-tick #2
• gauge - depends on Add c3-gauge #11, Add c3-chart size and color attributes #12