Full Due support, maskIRQ function

- Tested and now fully functional on Arduino Due
- Added support for the extended SPI functions: brings Due performance
up to par with Due managing the CSN   pin and settings
- Corrected issues with printDetails() on Due
- Changed added variables to staticly defined types: ie: uint16_t
instead of unsigned int
- I think this will work on all ARM based boards that use the Arduino
libs
- Added maskIRQ function - to be used in RF24Network sleep mode
- Changed csn(int mode) to csn(bool mode)
- Updated GettingStarted_CallResponse.ino example: Capture start time
AFTER printing to serial so measurement is more accurate

Author: TMRh20

README.md

@@ -2,7 +2,7 @@
 
 Design Goals: This library is designed to be...  
 
-* More complianct with the manufacturer specified operation of the chip  
+* More compliant with the manufacturer specified operation of the chip  
 * More reliable and feature rich  
 * Easy for beginners to use  
 * Consumed with a public interface that's similiar to other Arduino standard libraries  
@@ -14,6 +14,7 @@ April 2014: Optimization nearing completion
 * Changes to read() functionality have increased reliability and response  
 * Extended timeout periods have been added to aid in noisy or otherwise unreliable environments  
 * Delays have been removed where possible to ensure maximum efficiency  
+* Arduino Due fully supported with extended SPI functions
 * More! See the links below and class documentation for more info.  
 
 Please refer to: