restructured repository based on following standards:

https://github.com/HW-Core/directory-structure

src/cmake/macros/CheckBuildDir.cmake

@@ -0,0 +1,23 @@
+# Copyright (C) 
+#
+# This file is free software; as a special exception the author gives
+# unlimited permission to copy and/or distribute it, with or without
+# modifications, as long as this notice is preserved.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY, to the extent permitted by law; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+#
+# Force out-of-source build
+#
+
+string(COMPARE EQUAL "${CMAKE_SOURCE_DIR}" "${CMAKE_BINARY_DIR}" BUILDING_IN_SOURCE)
+
+if( BUILDING_IN_SOURCE )
+  message(FATAL_ERROR "
+    This project requires an out of source build. Remove the file 'CMakeCache.txt'
+    found in this directory before continuing, create a separate build directory
+    and run 'cmake path_to_project [options]' from there.
+  ")
+endif()