Calculate and use lengths according to protocols to fix issues with e.g. Nexus protocol

[enwi]

Other changes featured in this PR:

• Added linking instructions for MacOS
• Updated pilight to https://github.com/pilight/pilight/commit/ee7231263340dc08b97edf5dc184ee67d907b430
• Reduce variable scope of now and duration in interruptHandler

[enwi]

Does this PR meet everything we discussed on #53 @puuu ?

[puuu]

Ok, looks good, but I want to do a test on an ESP first.

Can you confirm receipt of Nexus signals?

[enwi]

I can test it on esp32 and esp8266, but will take some time

[puuu]

Yes, would be great.

[enwi]

I can confirm that it works on ESP8266 (Wemos D1 Mini) with SRX882

RF signal arrived [nexus][103] (0) {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}
RF signal arrived [nexus][103] (2) {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}
Valid message: [nexus] {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}
RF signal arrived [nexus][103] (3) {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}
RF signal arrived [nexus][103] (3) {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}
RF signal arrived [nexus][103] (3) {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}
RF signal arrived [nexus][103] (3) {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}
RF signal arrived [nexus][103] (3) {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}
RF signal arrived [nexus][103] (3) {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}
RF signal arrived [nexus][103] (3) {"id":103,"channel":0,"battery":1,"temperature":17.9,"humidity":71}

[puuu]

Great, that the nexus protocol works. I updated pilight in the master branch. You may can rebase to master without the pilight commits.

[puuu]

Thanks! I merged it into master.