examples: cleanup examples directory

Following changes are done as a part of cleanup:

1. Moved the platform specific `C` examples from top level examples/
directory to platform/ subdirectory and renamed helloedison.c to
gpio_edison.c

2. C specific examples are moved to a new c/ subdirectory. As a part
of this process, examples are modified to follow same standards
and few new examples are also added.

3. Include the newly added C examples to relevant API documentation

4. Ran clang-format for all source files in c/, c++/, platform/
subdirectories

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

examples/platform/firmata_curie_imu.c

@@ -0,0 +1,92 @@
+/*
+ * Author: Brendan Le Foll
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+
+#include "mraa.h"
+#include "mraa/firmata.h"
+
+#define FIRMATA_START_SYSEX 0xF0
+#define FIRMATA_END_SYSEX 0xF7
+#define FIRMATA_CURIE_IMU 0x11
+#define FIRMATA_CURIE_IMU_READ_ACCEL 0x00
+
+void
+interrupt(uint8_t* buf, int length)
+{
+    printf("reg read returned: %d, with buffer size %d\n", ((buf[6] & 0x7f) | ((buf[7] & 0x7f) << 7)), length);
+}
+
+int
+main()
+{
+    mraa_init();
+    //! [Interesting]
+
+    /**
+     * This example reads from the FirmataCurieIMU plugin
+     */
+
+    mraa_add_subplatform(MRAA_GENERIC_FIRMATA, "/dev/ttyACM0");
+    mraa_firmata_context firm = mraa_firmata_init(FIRMATA_CURIE_IMU);
+    if (firm == NULL) {
+        return EXIT_FAILURE;
+    }
+
+    mraa_firmata_response(firm, interrupt);
+
+    char* buffer = calloc(4, 0);
+    if (buffer == NULL) {
+        free(firm);
+        return EXIT_FAILURE;
+    }
+    buffer[0] = FIRMATA_START_SYSEX;
+    buffer[1] = FIRMATA_CURIE_IMU;
+    buffer[2] = FIRMATA_CURIE_IMU_READ_ACCEL;
+    buffer[3] = FIRMATA_END_SYSEX;
+
+    mraa_firmata_write_sysex(firm, buffer, 4);
+
+    sleep(1);
+
+    // stop the isr and set it again
+    mraa_firmata_response_stop(firm);
+    mraa_firmata_response(firm, interrupt);
+    mraa_firmata_write_sysex(firm, buffer, 4);
+
+    sleep(1);
+
+    // close everything and try again
+    mraa_firmata_close(firm);
+    firm = mraa_firmata_init(FIRMATA_CURIE_IMU);
+    mraa_firmata_response(firm, interrupt);
+    mraa_firmata_write_sysex(firm, buffer, 4);
+
+    sleep(10);
+
+    mraa_firmata_close(firm);
+    //! [Interesting]
+
+    return EXIT_SUCCESS;
+}