Added a test to confirm amalgamation worked

Added 'simple.cpp' which does the bare mimimum to confirm the amalgamation worked (compiled and run after the combine step). Split the embedded .basis files from the Emscripten test so they can be shared. Fixed an error in the creation script (which caused it to always fail). Corrected the syntax for the unused functions (tested with older, less forgiving compilers).

contrib/single_file_transcoder/examples/simple.cpp

@@ -0,0 +1,60 @@
+/**
+ * \file simple.cpp
+ * Bare minimum example of using the single-file \c basisu_transcoder.cpp.
+ * Opens an embedded \c .basis file to test that amalgamating the transcoder
+ * worked.
+ * \n
+ * Compile using:
+ * \code
+ *	cc -std=c++11 -lstdc++ simple.cpp
+ * \endcode
+ * 
+ * Example code released under a CC0 license.
+ */
+#include "../basisu_transcoder.cpp"
+
+using namespace basist;
+
+//********************************* Test Data ********************************/
+
+/**
+ * Basis Universal compressed 256x256 RGB texture source (with mipmaps).
+ * \n
+ * See \c testcard.png for the original. Generate using:
+ * \code
+ *	basisu -comp_level 5 -linear -global_sel_pal -y_flip -mipmap
+ * \endcode
+ */
+static uint8_t const srcRgb[] = {
+#include "testcard.basis.inc"
+};
+
+//****************************************************************************/
+
+/**
+ * Shared codebook instance.
+ */
+static etc1_global_selector_codebook* globalCodebook = NULL;
+
+/**
+ * Simple single-file test to test the transcoder can build and run.
+ */
+int main() {
+	basisu_transcoder_init();
+	if (!globalCodebook) {
+		 globalCodebook = new etc1_global_selector_codebook(g_global_selector_cb_size, g_global_selector_cb);
+	}
+	basisu_transcoder transcoder(globalCodebook);
+	if (transcoder.validate_header(srcRgb, sizeof srcRgb)) {
+		basisu_file_info fileInfo;
+		if (transcoder.get_file_info(srcRgb, sizeof srcRgb, fileInfo)) {
+			basisu_image_info info;
+			if (transcoder.get_image_info(srcRgb, sizeof srcRgb, info, 0)) {
+				printf("Success (file w: %d, h: %d, mips: %d)\n",
+					info.m_width, info.m_height, info.m_total_levels);
+				return EXIT_SUCCESS;
+			}
+		}
+	}
+	return EXIT_FAILURE;
+}