Tools: upgrade to gcc 4.8
usb_conf.h: do not redefine __packed if already defined

gcc 4.8 now provides this definition in some of its files. Keeping
the definition for other compilers though.
Tools: use the OS specific platforms to define ARM_SDK_URL

Windows now defines what to get but will still not install it
for you.
Sensors Simulated: deal with no home location

If HomeLocation is not set, do not generate invalid
Mag data since this is just bad simulation. Use a
reasonable value for HomeLocation.
Simulation: add IDLE_COUNT definition

This makes the simulators not hit 100% CPU since they
dont have as high idle counts as real hardware.
Simulator: create flash binary if missing

This reuses the code from the unit test and if the
flash file does not open it attempts to create one.
Simulation: do not use quaternion stabilization

Use the same code as the other targets for consistency.
UAVOHoTTBridge: reduced rx/tx-buffers and stack size. fixes a little bug in gps_fix_char.

Saved exactly 1092 bytes of RAM on all targets. Reduced RX and TX
buffers to minimal size and decreased stack size by 100. Added two
missing breaks in gps_fix_char calculation.
UAVOFrSKYSensorHubBridge: removed scaling

removed scaling for current and voltage
Merge pull request #1105 from janfietz/janfietz/frsky_batterystatus_fix

UAVOFrSKYSensorHubBridge: Fixed current and voltage scaling
Merge pull request #1097 from peabody124/sim_fixes

Sim usability fixes
Merge pull request #1099 from ernieift/ernieift/HoTT

UAVOHoTTBridge: save 1092 bytes of RAM on all targets.
Stabilization: get rid of AttitudePlus mode and always use trims

Having the trims object and an attitude mode that doesn't use them
is redundant. This now uses the trims in all modes, and to not use
them the value is set to zero (default).
Stabilization: drop the QUATERNION_STABILIZATION mode

This code is never used and has not been tested since all the new
modes were introduced. Lets delete it and reintroduce (and test)
it when or if desired. It also behaved strangely in simulation,
so may not have bugs.
Stabilization: minor refactoring for cleaner code

Now we always have trim angles simply put the setpoint in
those terms and use it for all the modes.
GCS: increment trim values when taking from transmitter

Now the system is always in the equivalent of previous "AttitudePlus"
mode, the trim should always be taken as a change in the setpoint
rather than an absolute value.
GCS: zero trim settings after leveling

After leveling the frame, rezero the trim settings. For most
people this will be the desired behavior and if there is a
residual trim offset they will probably wonder why it is not
flying level.
Merge pull request #1082 from peabody124/gcc48

Upgrade to gcc 4.8
AttiudePlus: comments from review

Mostly just header file changes
Merge pull request #1107 from peabody124/default_to_attitudeplus

Default to AttitudePlus