begin initial merge of 2.2 features

mw2.2-merged stuff:
* implemented profiles 0-2 (called 'setting' in mwiigui)
* merged in MSP changes including profile switch
* cleaned up rc / aux switch stuff in mw.c based on 2.2 rewrite
* main loop switch for baro/sonar shit adjusted
todo: basically the rest of 2.2 changes (i think some minor imu/gps/baro updates)
baseflight-specific stuff:
* made boxitems transmission dynamic, based on enabled features. no more GPS / camstab trash if it's not enabled
* cleaned up gyro drivers to return scale factor to imu code
* set gyro_lpf now controls every supported gyro - not all take same values, see driver files for allowed ranges, in case of invalid lpf, defaults to something reasonable (around 30-40hz)

maybe couple other things I forgot. this is all 100% experimental, untested, and not even flown. thats why there's  no hex.
merge is still ongoing.

git-svn-id: https://afrodevices.googlecode.com/svn/trunk/baseflight@294 7c89a4a9-59b9-e629-4cfe-3a2d53b20e61

src/board.h

@@ -56,6 +56,7 @@ typedef enum {
     FEATURE_SONAR = 1 << 10,
     FEATURE_TELEMETRY = 1 << 11,
     FEATURE_POWERMETER = 1 << 12,
+    FEATURE_VARIO = 1 << 13,
 } AvailableFeatures;
 
 typedef enum {
@@ -72,10 +73,11 @@ typedef uint16_t (* rcReadRawDataPtr)(uint8_t chan);        // used by receiver
 
 typedef struct sensor_t
 {
-    sensorInitFuncPtr init;
-    sensorReadFuncPtr read;
-    sensorReadFuncPtr align;
-    sensorReadFuncPtr temperature;
+    sensorInitFuncPtr init;                                 // initialize function
+    sensorReadFuncPtr read;                                 // read 3 axis data function
+    sensorReadFuncPtr align;                                // sensor align
+    sensorReadFuncPtr temperature;                          // read temperature if available
+    float scale;                                            // scalefactor (currently used for gyro only, todo for accel)
 } sensor_t;
 
 typedef struct baro_t