Flashify defines

[p-h-a-i-l]

As mentioned here: #55

Change lots of hardcoded magic numbers to flash stored values which can be updated via serial protocol.
Especially ADC parameters need to be update-able via protocol.

@btsimonh: We still need to have the default values somewhere. I'd still use defines but use them only for flash initialization. Do you know of a better way?

[btsimonh]

I'm happy with them in the non excluded part of config.h, and with allowing re-definition of them from the env, like you have:

#ifndef ADC1_MAX
  #define ADC1_MAX      4095        // max ADC1-value while poti at maximum-position (0 - 4095)
#endif

These would then be the defaults put into flash or used if the flash did not contain them. (short read of flash?).
On flash write, they would be written.