updated makefile for supporting different target architectures

use "ARCH=arch_name make"

restructured project folder, implementations and headers together under sources/

AARCH64_BUILD/variables.mk

@@ -0,0 +1,13 @@
+export CPP_COMPILER=aarch64-buildroot-linux-gnu-g++
+
+export BD=${PWD}AARCH64_BUILD/
+
+# headers are good even if from ARM
+
+# libraries must point to the right one
+
+RESOURCES_LOC=${PWD}../../resources/
+export WAYLAND_LIBRARIES=${RESOURCES_LOC}libraries/
+export EGL_LIBRARIES=${RESOURCES_LOC}libraries/
+
+export GLUT_L_D=${GLUT_D}AARCH64_BUILD/