Added support for Rain Gauge

Added Rain to SENSOR_PROPERTIES. Actually a copy of:

https://github.com/asphotographics/netatmo-api-python/commit/4bcc18b5174
f2f9a99d95fe8665b902d135f74f0
Changed check that a station is Netatmo device/mod

Use the as_weatherstation.app.NETATMO_STYPE_LOOKUP list to determine if
a station is a Netatmo device/module. Also, pass the station object to
as_weatherstation.read.netatmo.read() so it has a better idea of the
station type.
Station and type is passed in with read() params

AS_WS_READER_NETATMO.read() no longer has to figure out what kind of
station the device/module is.

Also converted tabs to four spaces.