Project restructuring and minor modifications

**Mainly restructured the project:**
- Renamed everything to PhishOD (from "Phish Tracks"
- Groups in Xcode now same in folder structure
- No more loose icon files floating around (Images.xcassets)
- Added convenience category on UIImage for icons

**Minor changes:**
- Added `COLOR_PHISH_GREEN` to audio scrubber bar
- Fixed `UISegmentedControl` centering issue:

<img src="https://cloud.githubusercontent.com/assets/3122471/3567822/9dba9d00-0b23-11e4-8574-33e445449b12.png" width="320" />
- Open a random show from menu panel if nothing playing
- Fixed appearance for `UIToolbars` (colors were inverse)