* BMP085 pressure sensor: fix temperature value data type
the data type for t (U_T) should be long according to the BMP085
datasheet (rev. 1.2, section 3.5). values over 32767 can indeed occur,
and in my case lead to a wrong value for the temperature (and
consequently also pressure).
note: this problem only occurs above a certain temperature (exact
value depends on the calibration, but I assume somewhere around 26°C).
* BMP085 pressure sensor: adapt data types and calculation
this adapts the data types and calculation to be consistent with the
datasheet (rev. 1.2, section 3.5). while I did not notice any issues,
using the wrong data types could trigger edge cases.