Firmware Release 3.0

Add support for the GET_MOTOR_1_PWM and GET_MOTOR_1_RPM commands. Fix…

…es longstanding issue with PWM not being reported in control panel.

Remove excessive LCD refresh delays to speed up interface.

2.8 release for Generation 4 Electronics

Bugfix: Thermocouple should report 1024C when it detects an error.

And, fix the fix.

Bump MB version to 2.2.

The release candidate for the v2.1 release of the motherboard firmware.

The release candidate for the v2.3 release of the extruder controller…

… firmware.

2.2 release to fix HBP heat issue