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/crc16.h

@@ -0,0 +1,34 @@
+#ifndef CRC16_H
+#define CRC16_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Derived from CRC algorithm for JTAG ICE mkII, published in Atmel
+ * Appnote AVR067.  Converted from C++ to C.
+ */
+
+extern unsigned short crcsum(const unsigned char* message,
+			     unsigned long length,
+			     unsigned short crc);
+/*
+ * Verify that the last two bytes is a (LSB first) valid CRC of the
+ * message.
+ */
+extern int crcverify(const unsigned char* message,
+		     unsigned long length);
+/*
+ * Append a two byte CRC (LSB first) to message.  length is size of
+ * message excluding crc.  Space for the CRC bytes must be allocated
+ * in advance!
+ */
+extern void crcappend(unsigned char* message,
+		      unsigned long length);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif