Expose box.name as environ var. to script

Allows script to perform logic based on BLIMPY_SHIPNAME
Mention "flavor" in example

Had to look through source code to find that I could set this.
Show internal DNS as well for status
Merge pull request #69 from jblaine/patch-4

Show internal DNS as well for status
Merge pull request #67 from jblaine/patch-3

Mention "flavor" in example
Merge pull request #66 from jblaine/patch-2

Expose box.name as environ var. to script
Serialize :tags to state file

Should be harmless, and I'm looking to use it.
Expose ship.tags in README

Found in the code that I could set this to alter EC2 tags
Merge pull request #71 from jblaine/master

Serialize ship.tags to state file, mention ship.tags in README
Use the debugger gem which actually works on 1.9
Forcing ssh_wait is considered harmful.

1. If your Blimpfile is misconfigured, you'll not get any diagnostics information.
2. When you press Ctrl+C, blimpy doesn't exit because it's just ssh getting killed (and blimp ignores that)

There appears to be no provision for handling options, so I just made it a separate command
function like this touching ARGV is abstraction violation, as it prevents other driver code from legitimately launching interactive shell.

 Better to let the calling command handle this
allow monkey-patching of Blimpy by the project (mainly to add more commands)
don't waste a line if there's no need to

Blimpy prints unnecessary empty line if the SSH connection goes through
fast enough. Don't do it.