Fixed #924 -- Updated homepage to better reflect our projects.

1. Resized the penguin logo so main header text can fit in 2 lines.
2. "Get Help" box replaces "Attend events".
4. Added new outreach links + pictures.
3. Added Twitter stream feed at bottom of page in blog widget.

Thanks Britta for making the mockup.
Merge pull request #197 from onceuponatimeforever/924

Issue #924 Update homepage to better reflect our projects.

Merging now. Huge thanks to @brittag and @onceuponatimeforever for making this happen,
along with surely many others.