Upgrade Foundation Icons to v3 - Round 2

Continues work of #153 to address #137

### Refactors V3 & Removes V2 Icons
* Refactored foundation icons v3 so that all foundation-icon code is in its own folder
* Removed [gem previously used to manage icons](https://github.com/zaiste/foundation-icons-sass-rails)

### Upgrades remaining pages to use v3 icons

#### Index / Homepage
![codemontage-2](https://f.cloud.github.com/assets/226228/1991181/7bdd12ec-8493-11e3-90af-4701d102dcdb.png)
![codemontagestartcodingicon-3](https://f.cloud.github.com/assets/226228/1991182/7e86b48a-8493-11e3-99b1-1637dfb48906.png)

#### Projects
![codemontagenewprojectsaveicon](https://f.cloud.github.com/assets/226228/1991140/658b0310-8492-11e3-8941-2dc5a3f34c44.png)

#### Organization
![codemontageushahidi-2](https://f.cloud.github.com/assets/226228/1991194/e57a95d0-8493-11e3-85e5-26ebcc8180eb.png)
![codemontageorganizationprojecticons-2](https://f.cloud.github.com/assets/226228/1991203/25742de0-8494-11e3-8f5f-a22f91b6d8fb.png)