examples: Remove heap allocation from C++ examples

Cleanup of UPM C++ examples.  Switched from heap allocation to
stack allocation when possible.  This simplifies the samples since it
removes the need for explicit memory management.  A script was used to
identify and replace pointer use.  To simplify the replace script, I
re-formatted the C++ examples using the UPM .clang-format file.
Unfortuantely this changes the look of the UPM C++ examples to a large
degree.  However, examples will now have a standard look/feel and
uniform formatting.

    * Ran clang-format w/provided UPM .clang-format file
    * Removed new's/delete's whenever possible (left those in interface
      examples)
    * Added IIO sensor library implementation of callback void* arg
    * Converted all sleeps to upm defined delays (added header when
      necessary)
    * Scrubbed CXX example includes

Signed-off-by: Noel Eck <noel.eck@intel.com>

examples/c++/apa102.cxx

@@ -23,9 +23,6 @@
  */
 
 #include "apa102.hpp"
-#include <iostream>
-#include <signal.h>
-#include <unistd.h>
 
 using namespace std;
 
@@ -34,18 +31,17 @@ main(int argc, char** argv)
 {
     //! [Interesting]
     // Instantiate a strip of 30 LEDs on SPI bus 0
-    upm::APA102* ledStrip = new upm::APA102(800, 0);
+    upm::APA102 ledStrip(800, 0);
 
     // Set all LEDs to Red
-    ledStrip->setAllLeds(31, 255, 0, 0);
+    ledStrip.setAllLeds(31, 255, 0, 0);
 
     // Set a section (10 to 20) to blue
-    ledStrip->setLeds(10, 20, 31, 0, 0, 255);
+    ledStrip.setLeds(10, 20, 31, 0, 0, 255);
 
     // Set a single LED to green
-    ledStrip->setLed(15, 31, 0, 255, 0);
+    ledStrip.setLed(15, 31, 0, 255, 0);
 
-    delete ledStrip;
     //! [Interesting]
     return 0;
 }