htu21d: update to correct code now under MIT license

Signed-off-by: William Penner <william.penner@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
mpl3115a2: sensor added

Signed-off-by: William Penner <william.penner@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
gas: fixed documentation typos and updated images

Signed-off-by: Mihai Tudor Panu <mihai.t.panu@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
ldt0028: Added support for LDT0-028 PZT film-based sensors

Signed-off-by: Sarah Knepper <sarah.knepper@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
grove: add grove button support and examples

Signed-off-by: Sarah Knepper <sarah.knepper@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
tp401: grove air quality sensor and examples

Signed-off-by: Mihai Tudor Panu <mihai.t.panu@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
grovetsl2561.jpeg: remove exec permissions on file

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
doxy2swig: fix runtime issue because off missing unicode encode

Fixes #14

Signed-off-by: Mihai Tudor Panu <mihai.t.panu@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
tp401: grove air quality sensor and examples

Signed-off-by: Mihai Tudor Panu <mihai.t.panu@intel.com>