Removed naze32 bootloader (unused on naze32)
Removed sventas i2c alternate driver - openpilot i2c driver works fine
Disabled PIOS_I2C_DIAGNOSTICS by default for i2c openpilot driver (it consumes a lot of memory/cpu)
Added support for MS5611 barometric pressure sensor
Enabled altitude module
Reduced heap usage to allow using altitude module