- 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
* webui: improve updater error message
* ota: properly check updater state and finalize on errors
* finish up ota handling refactor
* fail web upgrade when cannot find magic byte
* send updater status with no payload arg and always send payload with
* mention magic byte and flash mode in webui
* gzip magic
* make async ota at least usable. timeouts, show errors, try harder to find data after headers
* simplify setup and destruction
* cleanup class instantiations for ota and url
* handle default case of magicflashchipsize
* shorter
* blobs