Version 3.5.4

Compatible versions:

• RepRapFirmware 3.5.4
• DuetWebControl 3.5.4

API changes:

• Minor command fraction type has been changed from sbyte (signed byte) to int (signed integer)

Changed behaviour:

• M292 is prioritised to allow custom codes that create blocking message boxes
• Prioritised codes are preferrably sent to idle channels with the same firmware emulation type

Bug fixes:

• M99 could cause internal stack level corruption in macro files
• M32/M37 could override the file being printed (fixes #206)
• Fixed GetSerializedObjectModel in the API
• Don't lock job procesosr while waiting for SPI request and allow print cancellation requests to be aborted on SPI connection loss (fixes for potential rare deadlocks)