This removes requiring 'inspec' in bin/inspec and goes straight to
'inspec/cli'. It removes almost all the top-level requires in
inspec/cli.rb. This requires some autoloads and rearrangements of
requires to the command methods themselves.
```
% SLOW=1 time rake test:functional
before: Finished in 1072.442633s, 0.3264 runs/s, 1.9013 assertions/s.
after: Finished in 681.514579s, 0.5136 runs/s, 2.9919 assertions/s.
```
I'm positive there is more we can do.
Signed-off-by: Ryan Davis <zenspider@chef.io>
