HOSTNAME_MAX: Moved to curl_gethostname.h

Moved HOSTNAME_MAX #define into curl_gethostname.h rather than being
locally defined in curl_gethostname.c, curl_ntlm_msgs.c and smtp.c.

lib/curl_gethostname.c

@@ -28,9 +28,6 @@
 
 #include "curl_gethostname.h"
 
-/* Hostname buffer size */
-#define HOSTNAME_MAX 1024
-
 /*
  * Curl_gethostname() is a wrapper around gethostname() which allows
  * overriding the host name that the function would normally return.

lib/curl_gethostname.h

@@ -22,6 +22,10 @@
  *
  ***************************************************************************/
 
+/* Hostname buffer size */
+#define HOSTNAME_MAX 1024
+
+/* This returns the local machine's un-qualified hostname */
 int Curl_gethostname(char *name, GETHOSTNAME_TYPE_ARG2 namelen);
 
 #endif /* HEADER_CURL_GETHOSTNAME_H */

lib/curl_ntlm_msgs.c

@@ -93,9 +93,6 @@
 /* The last #include file should be: */
 #include "memdebug.h"
 
-/* Hostname buffer size */
-#define HOSTNAME_MAX 1024
-
 /* "NTLMSSP" signature is always in ASCII regardless of the platform */
 #define NTLMSSP_SIGNATURE "\x4e\x54\x4c\x4d\x53\x53\x50"