Many changes - tidying up the extensions interfaces.

Updating the GPIO command - new command - allreadall
ScrollPhat code
max31855 code (tested with adafruit breakout board)
more tests
updated rht03 code

Raspberry Pi v3 support.

gpio/readall.c

@@ -215,7 +215,14 @@ static void readallPhys (int physPin)
 }
 
 
-void cmReadall (void)
+/*
+ * allReadall:
+ *	Read all the pins regardless of the model. Primarily of use for
+ *	the compute module, but handy for other fiddling...
+ *********************************************************************************
+ */
+
+static void allReadall (void)
 {
   int pin ;
 
@@ -292,12 +299,16 @@ static void plus2header (int model)
     printf (" +-----+-----+---------+------+---+--B Plus--+---+------+---------+-----+-----+\n") ;
   else if (model == PI_MODEL_ZERO)
     printf (" +-----+-----+---------+------+---+-Pi Zero--+---+------+---------+-----+-----+\n") ;
-  else
+  else if (model == PI_MODEL_2)
     printf (" +-----+-----+---------+------+---+---Pi 2---+---+------+---------+-----+-----+\n") ;
+  else if (model == PI_MODEL_3)
+    printf (" +-----+-----+---------+------+---+---Pi 3---+---+------+---------+-----+-----+\n") ;
+  else
+    printf (" +-----+-----+---------+------+---+---Pi ?---+---+------+---------+-----+-----+\n") ;
 }
 
 
-void piPlusReadall (int model)
+static void piPlusReadall (int model)
 {
   int pin ;
 
@@ -314,6 +325,13 @@ void piPlusReadall (int model)
 }
 
 
+/*
+ * doReadall:
+ *	Generic read all pins called from main program. Works out the Pi type
+ *	and calls the appropriate function.
+ *********************************************************************************
+ */
+
 void doReadall (void)
 {
   int model, rev, mem, maker, overVolted ;
@@ -328,10 +346,21 @@ void doReadall (void)
 
   /**/ if ((model == PI_MODEL_A) || (model == PI_MODEL_B))
     abReadall (model, rev) ;
-  else if ((model == PI_MODEL_BP) || (model == PI_MODEL_AP) || (model == PI_MODEL_2) || (model == PI_MODEL_ZERO))
+  else if ((model == PI_MODEL_BP) || (model == PI_MODEL_AP) || (model == PI_MODEL_2) || (model == PI_MODEL_3) || (model == PI_MODEL_ZERO))
     piPlusReadall (model) ;
   else if (model == PI_MODEL_CM)
-    cmReadall () ;
+    allReadall () ;
   else
     printf ("Oops - unable to determine board type... model: %d\n", model) ;
 }
+
+/*
+ * doAllReadall:
+ *	Force reading of all pins regardless of Pi model
+ *********************************************************************************
+ */
+
+void doAllReadall (void)
+{
+  allReadall () ;
+}