Random number generator class based on ChaCha

doc/Doxyfile

@@ -753,6 +753,7 @@ IMAGE_PATH             = ../libraries/BlinkLED/examples/Cylon \
                          ../libraries/LCD/examples/HelloWorld \
                          ../libraries/LCD/examples/Form \
                          ../libraries/RTC/examples/AlarmClock \
+                         ../libraries/Crypto \
                          ../libraries/DMD \
                          ../libraries/IR \
                          ../libraries/I2C

doc/crypto.dox

@@ -30,6 +30,7 @@
 \li Block cipher modes: CTR, CFB, CBC, OFB
 \li Stream ciphers: ChaCha
 \li Hash algorithms: SHA1, SHA256, BLAKE2s
+\li Random number generation: \link RNGClass RNG\endlink, TransistorNoiseSource
 
 All cryptographic algorithms have been optimized for 8-bit Arduino platforms
 like the Uno.  Memory usage is also reduced, particularly for SHA1 and SHA256

doc/mainpage.dox

@@ -94,6 +94,7 @@ realtime clock and the LCD library to implement an alarm clock.
 \li Block cipher modes: CTR, CFB, CBC, OFB
 \li Stream ciphers: ChaCha
 \li Hash algorithms: SHA1, SHA256, BLAKE2s
+\li Random number generation: \link RNGClass RNG\endlink, TransistorNoiseSource
 
 More information can be found on the \ref crypto "Cryptographic Library" page.