- general conversion from .ino modules into a separate .cpp files
- clean-up internal headers, place libraries into .h. guard .cpp with _SUPPORT flags
- fix some instances of shared variables instead of public methods
- tweak build system to still build a single source file via os environment variable ESPURNA_BUILD_SINGLE_SOURCE
* Update encoder
- import modified Encoder library
- customize minimum delta value
* minimum delta in header config
* fixup! minimum delta in header config
* fix dead code, actually use interrupts
* move static class methods to normal funcs, apply namespace
* drop hardcoded register use
- use peripheral api (see cores/esp8266/esp8266_peri.h)
- remove bitmask and register struct members
* add a note about changes
* fixup! add a note about changes