Add bash bang to several shell scripts

Adds ```#!/bin/bash``` to the top of a few shell scripts that didn't have it.

I was having crazy errors running setup.sh from bash on Mac OS X 10.8.2 without this. Adding this fixed it. For example:

```
-bash(455) malloc: *** error for object 0x800007f84c2c0002: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
Abort trap: 6
```