5.9.1 20171107
* Add external sensor function pointer interface to
enable easy sensor addition
* Add support for ADS1115 to be enabled in
user_config.h and needs libraries i2cdevlib-Core and i2cdevlib-ADS1115
(#338, #660)
* Fix Backup Configuration file download failure by
defining proper file size (#1115)
* Fix Exception 26 and empty console
screen after usage of command WakeupDuration (#1133)
* Fix some changed
iTead web links in README.md (#1137)
