ds18b20: rewrite C++ to wrap C, add FTI, update examples

Previously, the C++ and C versions of this driver were separate.  Now
the C++ implementation wraps the C implementation.

In addition, the C++ init() function has been deprecated.  It
currently does nothing, and examples have been modified to remove it's
calls.  This function will be removed in a separate release.

The examples have been further modified to update all detected devices
and print their respective temperatures, instead of only reporting the
on the first device detected.

Signed-off-by: Jon Trulson <jtrulson@ics.com>

src/ds18b20/pyupm_ds18b20.i

@@ -8,6 +8,8 @@
 
 %feature("autodoc", "3");
 
+%include "ds18b20_defs.h"
+%include "ds18b20.hpp"
 %{
     #include "ds18b20.hpp"
 %}