make rs485 modules compile again
remove compiler warning about unused 'is_e6'
make ds2450 code compile without warnings
fixed the warning the right way
Merge pull request #187 from sauttefk/e6-upstream2

autotest for rs485 modules; fix errors and warnings
Merge remote-tracking branch 'upstream/master' into e6-upstream1
Merge branch 'e6-upstream1' of github.com:sauttefk/ethersex into e6-upstream1