new structs, telemetry values & MQTT cmds

[nerdoug]

• 2020-07-10 DE: -re-structure the structures, merging in most of the isolated by related values
• -make use of single motor ISR unconditional, optimizing out if statements
• -rename robot struct to attributes, & put non-changing attributes in it, including non-duplicated wheel stuff
• -rename metadata struct to health, and metadataMsg to healthMsg
• -create left and right structs, which contain wheel-specific balancing params, for now
• -remove baltel and metadata MQTT commands and replace with new pseudo variables for setvar command:
• balTelOFF, balTelCON, balTelMQTT, healthMsgOFF, healthMsgCON and healthMsgMQTT
• 2020-07-13 -added AMDP_PRINT2() and AMDP_PRINT2LN() to declutter debug output
• -made MQTT QOS a compile time parameter, controlled by MQTTQos
• -implement MQTT command getvars which writes control variables to MQTT, and remove param dump from setvar

[nerdoug]

merge hung with a message saying it was checking to see if the merge had conflicts. aborted after 10 minutes & will retry