Update protocol version to 1.38

[modest]

• Converted the 1.38 (2017-04-07) protocol spec from XSLX to YAML
  • Required some dirty hacks and overrides to the importer Python, not included here
• Manually merged the changed YAML into the existing YAML
  • Preserved existing hand edits
• Minor cleanup of the YAML
  • Added names to some unnamed commands

Closes #110

Adds support for 21 new models:

• DRC-R1
• DRX-2.1
• DRX-3.1
• DRX-4.1
• DRX-5.1
• DRX-7
• DRX-R1
• DTM-7
• PR-RZ5100
• TX-8270(Ether)
• TX-NR474(Ether)
• TX-NR575(Ether)
• TX-NR575DAB(Ether)
• TX-NR575E(Ether)
• TX-NR676(Ether)
• TX-NR676E(Ether)
• TX-NR777
• TX-RZ1100
• TX-RZ3100
• TX-RZ620
• TX-RZ720
• TX-RZ820

Adds support for new commands (all are "on supported models"):

• setting input to USB DAC, Line, Line 2, Optical, and Coaxial
• setting Direct mode
• setting an equalizer preset
• setting lock range
• setting s. bass
• toggling the dialog control
• forcing a firmware update
• retrieving temperature data
• checking battery status
• controlling the built-in CD player
• setting Bluetooth on and off

[modest]

Travis CI failure is due to the test failing to download Python 3.3. The actual tests succeeded.

[miracle2k]

@modest Fantastic work!

There is still the open ticket https://github.com/miracle2k/onkyo-eiscp/issues/74 which AFAIK is basically some commands in the main zone missing because they have been moved to a separate tab in the excel spreadsheet file, and are now in NET(USB).

Do you happen to have the importer hacks available? We might want to merge them (future updates may require similar changes to the importer). Or, could you run it again with the NET-USB tab included in the main zone commands?