deps.labjack: support building for windows

The only pthread functionality this seems to use is mutexes, which are
(fortunately) theoretically trivial to wrap for windows. This
compiles, though it is not clear if it actually works correctly.

deps/labjack/ljacklm/libljacklm/ljacklm.c

@@ -23,7 +23,14 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <pthread.h>
+
+#if defined(LJACKLM_USE_WINDOWS_MUTEX_SHIM)
+	#include <windows.h>
+	#include "windows_mutex_shim.h"
+#else
+	#include <pthread.h>
+#endif // LJACKLM_USE_WINDOWS_MUTEX_SHIM
+
 #include "labjackusb.h"
 
 
@@ -286,7 +293,9 @@ long GetU12Information( HANDLE hDevice,
 					    long *fcddMaxSize,
 					    long *hvcMaxSize);
 
+#if !defined(LJACKLM_USE_WINDOWS_MUTEX_SHIM)
 unsigned long GetTickCount( void);
+#endif
 
 
 __attribute__((constructor))
@@ -7266,6 +7275,7 @@ long GetU12Information( HANDLE hDevice,
 }
 
 
+#if !defined(LJACKLM_USE_WINDOWS_MUTEX_SHIM)
 //======================================================================
 //GetTickCount:	Implementation of GetTickCount() for Unix.  Returns the
 //				current time, expressed as millisconds since the Epoch 
@@ -7276,3 +7286,4 @@ unsigned long GetTickCount( void)
 	gettimeofday(&tv, NULL);
 	return (tv.tv_sec * 1000) + (tv.tv_usec / 1000);
 }
+#endif