Add sending commands to WSJTX

[stephenhouser]

Create or modify so that you can send commands/messages to the WSJTX host. Currently the nodes here only receive data from the host. The protocol allows sending commands to:

• Initiate a QSO
• Log a QSO
• Halt TX

Also with multiple instances of WSJT-X. Each instance has a unique name. The instance names appear in the status message as "id." In the WSJT communications document the "id" must be included in the command to WSJT. Use the "id" from the WSJT status packet to build a list of available instances, build a pull-down selector for the same, and use the selected instance to build the WSJT Send node configuration.

(Thank you Alan WA9WUD for these suggestions)

[stephenhouser]

Commit 0775137 starts adding these features

• heartbeat
• clear
• halt_tx
• reply

[stephenhouser]

Commit ed9a0fb has the bulk of this work completed for all the "in" messages.

[stephenhouser]

Resolved with release of v2.0 in bdcea7f