Add advanced settings

[smurfy]

Add some way to integrate advanced settings.

Separate screen with table like structure to enable non mainstream options.
Fueled by update.xml and defines.

Before starting this feature we need some examples for additional defines we could need and use in the advanced settings.

[smurfy]

Stuff for advanced settings:

• BOARD_VOLTAGE_MIN
• Disable internal compass (DISABLE_INTERNAL_MAG)

[d-v]

Hello Smurfy,
Setting PWM (1-8) does not work when I'm compiling MPNG source code. I had to compile from source since I needed to change orientation of FC board. Now RC doesn't work, and I assume this is because I use PWM. Could you add an option in the flash tool to change orientation? I love the simplicity of the flash tool. 👍
Thanks!