Renamed DaemonSource/Sink to Remote
Now that SDRdaemon is decommissioned the term "daemon" does not correspond to anything. "Remote" is a better naming for what concerns the remote operation of SDRangel. This is the first part of the change affecting only the channels.
Other changes and fixes
- XTRX: refactored GPS lock test using workaround using change in 1PPS iterval clock counts. Fixes hanging for 1PPS signal
- Windows build: fallen back to libusb 1.0.21
- Voice type modulators: corrected documentation on sound file input format
- Fix of typo in start-stop REST API examples script