Cleanup warnings generated by GCC. Make some values static/const.
Fix GCC unused-but-set-variable warnings
Fix 'no effect' GCC warnings.  EOL whitespace cleanups.
Fix unused variable.  Fix signed/unsigned char usage warnings.  EOL Whitespace cleanups.
Fix unused variable warning.  Delete apparently unused local variables and empty if block.
Fix unused variable warnings.  EOL whitespace cleanups.
OLIMEXINO - Use SPI include.
Fix GCC unused variable warnings for #ifdef'd out code.
Fix IDE errors when platform does not use BARO.
Cleanup software serial implementation.  Compile with SOFTSERIAL_19200_LOOPBACK to test.  Without the define the implementation will have no effect.  Next step is to add a 'feature' to enable softserial and settings for the baud rate.  Note, only READ is currently supported, write will come later.  The highlevel api calls are used in main.c.  Uart implementation needs cleanup to make serial port code generic, see uart files for details.