Increase data structures handled by scans

[danielspofford]

Resolves #36.

This was achieved by ensuring that when deserializing advertising
reports, portions of the binary that cannot be deserialized should not
cause a chain reaction of failure. Previously this would cause devices
not to show up in the results.

• ArrayedData: return an error instead of crashing
• AdvertisingReport: use the result of Device.deserialize regardless of
  status
• Device
  • cleanup bad doctests
  • simplify some serialization clauses to ensure the input binary is
    returned on error
• Transport
  • improve documentation
  • LE is always a handler