add mp3 player code

Code/MP3Player/YAHAL_import.cmake

@@ -0,0 +1,30 @@
+# This script tries to locate the YAHAL root
+# folder and reads the YAHAL_init.cmake file.
+
+# Check if we can get the path from a environment variable
+if (DEFINED ENV{YAHAL_DIR} AND (NOT YAHAL_DIR))
+    set(YAHAL_DIR $ENV{YAHAL_DIR})
+    message("Using YAHAL_DIR from environment ('${YAHAL_DIR}')")
+endif()
+
+# Check if we need to locate the YAHAL root directory
+if (NOT YAHAL_DIR)
+    message("Trying to find YAHAL ...")
+    find_path(YAHAL_DIR .yahal_version . .. ../.. ../../.. ../../../..)
+endif ()
+
+# Try to resolve a relative path
+get_filename_component(YAHAL_DIR "${YAHAL_DIR}" REALPATH BASE_DIR "${CMAKE_CURRENT_LIST_DIR}")
+if (NOT EXISTS ${YAHAL_DIR})
+    message(FATAL_ERROR "Directory '${YAHAL_DIR}' not found")
+endif ()
+
+# Check if YAHAL_DIR points to the correct folder.
+set(YAHAL_INIT_CMAKE_FILE ${YAHAL_DIR}/cmake/YAHAL_init.cmake)
+if (NOT EXISTS ${YAHAL_INIT_CMAKE_FILE})
+    message(FATAL_ERROR "Directory '${YAHAL_DIR}' does not appear to be a YAHAL root folder")
+endif ()
+
+# Finally include the init-script
+include(${YAHAL_INIT_CMAKE_FILE})
+