Include pthread.h in the implementation instead of the header.

include/empthread.h

@@ -87,7 +87,6 @@ typedef struct lwpSem empth_sem_t;
 #endif /* EMPTH_LWP */
 
 #ifdef EMPTH_POSIX
-#include <pthread.h>
 #define EMPTH_FD_READ   0x1
 #define EMPTH_FD_WRITE  0x2
 

src/lib/empthread/pthread.c

@@ -40,6 +40,7 @@
 
 #include <errno.h>
 #include <limits.h>
+#include <pthread.h>
 #include <signal.h>
 #include <stdarg.h>
 #include <stdio.h>