WIP: Moved sources int src/, separated most of the source code from Perl.

The XS was left only for the unit / integration tests, and it links
libslic3r only. No wxWidgets are allowed to be used from Perl starting
from now.

src/avrdude/main-standalone.c

@@ -0,0 +1,9 @@
+#include "avrdude.h"
+
+
+static const char* SYS_CONFIG = "/etc/avrdude-slic3r.conf";
+
+int main(int argc, char *argv[])
+{
+	return avrdude_main(argc, argv, SYS_CONFIG);
+}