Fixed gravity settings dialog.
GCS: Fix to suppress lots of debugging messages

The rich alarms change introduced a bug which caused spewing
debug messages.
Merge pull request #377 from kubark42/gravity-dialog

Fixed gravity settings dialog.
Merge pull request #398 from peabody124/alarms_fix

GCS: Fix to suppress lots of debugging messages
Added header file with common physical constants.
Updated library functions to use physical constants file.
Updated flight modules to use physical constants file.
Updated PiOS files to use physical constants file.
Updated GCS files to use physical constants file.
Added the shared API directory to simulator targets.
Fixes for header files, floating point trig functions, and incorrect
conversions.
Added shared/api to GCS include directory.
HomeLocation: Remove unused "g_e" field

We can add it back in if we start using it, but then we need
to use it reliably.  As it was this value was simply set and
then wasted memory.
Fixed missing newline.
Merge pull request #399 from peabody124/no_ge

HomeLocation: Remove unused "g_e" field
Calibration: Add doxygen header describing class function
UAVTalk: Fix crash when requesting update of unknown object

UAVTalk would check whether an unknown object was single instance
even if the object type was unknown, which caused a segfault.  This
value is only used to validate the payload length (possibly an
unnecessary check) so now that check is not applied if the object
is unknown.

The response to an OBJ_REQ for an unknown object is simply to return
a NAK packet so this should keep multiple instance objects ACK'ing
properly while solving the segfault for unknown objects.

Any non OBJ_REQ message should not even reach this far as they should
error our with a bad object type.

Fixes #80
Fixes #358
Resolved merge conflict.
flyingf3: raised stack size of eventdispatcher from 130 to 256 words
Rationale behind 130 was that it is the setting which works for CopterControl.
Turns out that it is too tight for FlyingF3.
Merge pull request #328 from kubark42/phys-constants

Group all physical constants into one file