updated makefile for supporting different target architectures

use "ARCH=arch_name make"

restructured project folder, implementations and headers together under sources/

.gitignore

@@ -0,0 +1,7 @@
+*.o 
+*.exe
+# the order is important, an ignore definition overrides the preceding NOT_ignore
+IA64_BUILD/**
+!IA64_BUILD/variables.mk
+AARCH64_BUILD/**
+!AARCH64_BUILD/variables.mk