Unify a bunch of debug fail messages to a single point. More needed.
statusRequest is now public
Don't return battery level in percentage
Fix a few problems with the lib linking with debug on.
Merge branch 'xxxajk' of github.com:felis/USB_Host_Shield_2.0 into xxxajk
Merge pull request #44 from felis/xxxajk

Xxxajk and done.