Merge pull request #11 from proan/hydro-devel

Fixes proan/bosch_drivers#4.
Merge pull request #13 from proan/sub20

sub20_interface
Merge pull request #15 from proan/sub20

libsub20
Now chasing a linking issue with libsub20 and libusb.
Merge branch 'hydro-devel' into sub20
Merge remote-tracking branch 'upstream/hydro-devel' into hydro-devel
Merge remote-tracking branch 'upstream/sub20' into sub20
Adding Arduino firmware files. Not catkin packages!
Merge pull request #17 from proan/arduino

Adding Arduino firmware files. Not catkin packages!
Rename of "internal" to "built-in" to work around Arduino's #define of all variables.
Renamed header file to better reflect variable rename.
Additional renames.
Merge pull request #18 from proan/arduino

Rename of "internal" to "built-in" to work around Arduino's #defines
Merge branch 'hydro-devel' into bma180
Merge branch 'hydro-devel' into sub20
Added byte that tells arduino to use gpio write or read
Changed the data type of read to a reference to get the read value
Fixed built in device type in gpio read
Merge pull request #19 from sebEg/gpio-develop

We should change the rest of the read() functions to also do pass-by-reference.
Added byte that tells arduino to set pwm signal