MixEffect Module 3.0 for Companion 3.0

[adamtow]

First version of the MixEffect Module for Companion 3.0. Includes the following changes and improvements:

• Feedbacks and variable work done by Darin Pope.
• Module upgrade for Companion 3.0 by Caleb Wishart.
• Added support for new ATEM Television Studio HD8 and HD8 ISO switchers.

[adamtow]

Merging the 3.x branch to master.