Spelling correction for DHT11
Bug fixes and adjustments based on field test

- Fixed a bug that caused SD module to fail writing when trying to do so
in constructor, before setup() is called (just removed header line
check)
- Changed triggeredHumidity check to short term average, as long term is
too slow, and most likely we will not get back to that level fast enough
- Added temperature in the log output
- Added sensor reading error to the log output
- Removed debug code for analog read while not connected to the sensor
- Adjusted buzzer time to 200ms, as we'll be retrying to read sensor
every second, so we don't want to have a continuous buzz, but rather
short pings
- Adjusted how often and how far back we're looking for statistics, as
initial field test shows one hour with 10 sec resolution is an overkill