- Sensors summary now shows you how man compasses you have
- Fix for APM accel cal. Can only use first accel offsets.

I removed some needed headers from a top level file which then causes a
ripple effect downstream

I know that some people belive that goto's are devil's work
but sometimes (like chaining if/elses for failures) it can
actually simplify the code for a better readability and
improved speed.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

Strings can be expensive to create, all the issues with allocation,
copy of the char members, conversion to UTF-16. QStringLiteral creates
one in compile time.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

virtual marks a method for inclusion on a v-table, but we don't want
the methods of classes that won't be inheritable to have a v-table,
we want, however, to issue a warning if somebody try to inherit
that specific class and reimplement those methods.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>