Fix MSVC compile by removing unistd.h and defining our own rig_useconds_t

https://github.com/Hamlib/Hamlib/issues/301

dummy/flrig.h

@@ -28,7 +28,7 @@
 #include <sys/time.h>
 #endif
 
-#define BACKEND_VER "20200510"
+#define BACKEND_VER "20200613"
 
 #define EOM "\r"
 #define TRUE 1

include/hamlib/rig.h

@@ -2743,8 +2743,8 @@ extern HAMLIB_EXPORT(int) rig_set_vfo_opt(RIG *rig, int status);
 
 
 // cppcheck-suppress *
-#include <unistd.h>
-extern HAMLIB_EXPORT(int) hl_usleep(useconds_t msec);
+typedef unsigned long rig_useconds_t;
+extern HAMLIB_EXPORT(int) hl_usleep(rig_useconds_t msec);
 
 //! @endcond
 

src/misc.h

@@ -100,7 +100,7 @@ extern HAMLIB_EXPORT(void) rig_force_cache_timeout(struct timeval *tv);
 
 extern HAMLIB_EXPORT(setting_t) rig_idx2setting(int i);
 
-extern HAMLIB_EXPORT(int) hl_usleep(useconds_t usec);
+extern HAMLIB_EXPORT(int) hl_usleep(rig_useconds_t usec);
 
 extern HAMLIB_EXPORT(double) elapsed_ms(struct timespec *start, int start_flag);
 

src/sleep.c

@@ -50,7 +50,7 @@ extern "C" {
 // In order to stop the usleep warnings in cppcheck we provide our own interface
 // So this will use system usleep or our usleep depending on availability of nanosleep
 // This version of usleep can handle > 1000000 usec values
-int hl_usleep(useconds_t usec)
+int hl_usleep(rig_useconds_t usec)
 {
     int retval = 0;
 
@@ -85,12 +85,13 @@ unsigned int sleep(unsigned int secs)
 }
 
 
+#if 0
 /**
  * \brief microsecond sleep
  * \param usec is microseconds to sleep
  * This does not have the same 1000000 limit as POSIX usleep
  */
-int usleep(useconds_t usec)
+int usleep(rig_useconds_t usec)
 {
     int retval;
     unsigned long sec = usec / 1000000ul;
@@ -106,6 +107,7 @@ int usleep(useconds_t usec)
 
     return 0;
 }
+#endif
 
 #endif // HAVE_NANOSLEEP
 #ifdef __cplusplus

src/sleep.h

@@ -28,7 +28,7 @@
 __BEGIN_DECLS
 
 /* Hamlib internal use, see rig.c */
-int hl_usleep(useconds_t usec);
+int hl_usleep(rig_useconds_t usec);
 
 __END_DECLS