Add support for encoder

[prasimix]

Encoder support should include the following features:

1. When encoder is enabled (add this as a new option into conf.h) one can use encoder immediately on main page.
2. Also if encoder is enabled allow change of output values on all other pages that contains channel info on the right side.
3. We can add encoder also on the keypad page
4. When encoder switch is pushed (ENC_SW input) generate click sound if that option is enabled.
5. Add encoder page under System settings with the following options:

• Confirmation: Yes/No
• Moving up speed: Selection from 1 to 10
• Moving down speed: Selection from 1 to 10 (by default 3-4 faster then moving up speed)

Add the following pin definition:

static const uint8_t ENC_SW = 64;

Resources:

• Buxtronix: Rotary encoders, done properly

[prasimix]

When enters keypad page and encoder is enabled, use currently set value (e.g.OVP that is set to 20 V) instead of empty value that corresponds to 0.00 V.

[prasimix]

Ignore switch push if limit exceed error is displayed and Selection option is selected.

[prasimix]

Fixed