setup scripts failures

[kerrizor]

Blindly going through setup instructions, I used the setup script. It failed on two different errors that cause 'thin' to silently fail:

1 - homebrew installed mongodb correctly, but did not start it (nor do the instructions point out that we need to start mongodb.) Now connection to mongo can be made, so thin exits. It would be handy if the script could start mongo for us, as well.

2 - since thin is not in the Gemfile, it fails to start (addressed in #760 ?)

[kerrizor]

Happy to tackle No. 1 here - better to:

A) add mongodb to launchctl
B) just launch mongodb without adding to launchctl
C) print out some instructions about the 2 options

..in general this issue is something most devs can figure out and handle, but I figured I'd mention it as it creates a kind of "trip on the missing step" feeling.

[colindean]

I know I prefer to have mongodb running in a terminal foreground when I’m using it for anything.