More Responsive UI

# Changes
- [x] Background image now in Jumbotron and more responsive 
- [x] Phrase `Hack-A-Week` in title now will not separate in smaller displays
- [x] Updated README
- [x] Added screenshots
- [x] Google Map iFrame is now more responsive on both larger and smaller screens
- [x] And of course merged the latest changes from `gh-pages` and `master` so `origin master` will now be up-to-date :wink: 
- [x] Updated GitIgnore to exclude Mac OS X system files.

# Screenshots
**Note:** Ignore that weird line in the header that looks like a scrollbar.
## Mobile (iPhone)
![127 0 0 1 8000 -640x1136](https://cloud.githubusercontent.com/assets/1885333/2685966/322c757a-c1dd-11e3-852d-c31f1acd0b30.png)
## Desktop
![127 0 0 1 8000 -1366x768](https://cloud.githubusercontent.com/assets/1885333/2685965/3221deb2-c1dd-11e3-9f73-194622920122.png)