100% Match of MxDSFile (#51)

* 100% Match of MxDSFile

* ...almost, MxDSFile::Open is still not quite matching but all of the
  other methods are 100% matching.

* Turns out that most of the virtual methods and some of the members are
  actually on the MxDSSource base class, which I've pulled out as part
  of this.

* In order to implement the methods I added the MXIOINFO class, which
  seems to be a thin wrapper around the MMIOINFO windows structure. We
  can tell this because MMIOINFO::~MMIOINFO was included in the DLL
  exports, and calls down to a function which deconstructs something
  looking exactly like MMIOINFO.

* Add mxdssource.cpp

* mattkc feedback

* some accuracy improvements

* Use FOURCC macro

* Tirival solve in mxioinfo.cpp

* Update mxdsfile.cpp

0xFFFFFFFF -> -1

---------

Co-authored-by: Christian Semmler <mail@csemmler.com>

LEGO1/mxioinfo.cpp

@@ -0,0 +1,49 @@
+#include "mxioinfo.h"
+
+// OFFSET: LEGO1 0x100cc800
+MXIOINFO::MXIOINFO()
+{
+  memset(&m_info, 0, sizeof(MMIOINFO));
+}
+
+// OFFSET: LEGO1 0x100cc820
+MXIOINFO::~MXIOINFO()
+{
+  Close(0);
+}
+
+// OFFSET: LEGO1 0x100cc830
+unsigned short MXIOINFO::Open(const char *filename, DWORD fdwOpen)
+{
+  return 0;
+}
+
+// OFFSET: LEGO1 0x100cc8e0
+void MXIOINFO::Close(long arg)
+{
+  
+}
+
+// OFFSET: LEGO1 0x100cc930
+unsigned long MXIOINFO::Read(HPSTR pch, LONG cch)
+{
+  return 0;
+}
+
+// OFFSET: LEGO1 0x100cca00
+LONG MXIOINFO::Seek(LONG lOffset, int iOrigin)
+{
+  return 0;
+}
+
+// OFFSET: LEGO1 0x100ccbc0
+void MXIOINFO::SetBuffer(LPSTR pchBuffer, LONG cchBuffer, LONG unk)
+{
+  
+}
+
+// OFFSET: LEGO1 0x100cce60
+unsigned short MXIOINFO::Descend(LPMMCKINFO pmmcki, const MMCKINFO *pmmckiParent, UINT fuDescend)
+{
+  return 0;
+}