This commits add documentation to the HDC1000 params and adds generic
exclude patters to the doc check, so that when boards provide custom
HDC1000 params they do not need to document them again. The reasoning
is that the documentation in the central place is sufficient.
- cleaned up interface
- made read functions return phyical values
- made resolution configurable at initialization time
- added default parameter configuration file
- added SAUL support for the driver
