catapult launch detection: fix integration logic
Improve startup and payload handling
Support additional payload commands and let commander ignore them
Ignore single channels during PWM output
Merge pull request #1323 from hsteinhaus/ignore_channels2

Ignore single channels during PWM output
Merge pull request #1321 from PX4/startup_payload

Improve startup and payload handling
Merge pull request #1322 from PX4/payload_commands

Support additional payload commands and let commander ignore them
Merge pull request #1302 from PX4/catapultlaunchdetectorhotfix

catapult launch detection: fix integration logic