Merge pull request #6 from Dessimat0r/dht22_tunning

DHT22 finall timming fixes. Other small fixes by Dessimat0r
get out the beta label
Make an 0xFF and to sum
some times it can be bigger than 0xFF and it will trigger an checksum error
Merge commit 'b10cd8706cc73e4d20e84c5f8710e395f50b0d89' into dht22_tunning