Put prototypes for the functions exported by wcwidth.c in putty.h, and remove

one from terminal.c.  Have wcwidth.c include putty.h to get its prototypes.

[originally from svn r2377]

putty.h

@@ -599,6 +599,12 @@ char *cp_enumerate (int index);
 char *cp_name(int codepage);
 void get_unitab(int codepage, wchar_t * unitab, int ftype);
 
+/*
+ * Exports from wcwidth.c
+ */
+int wcwidth(wchar_t ucs);
+int wcswidth(const wchar_t *pwcs, size_t n);
+
 /*
  * Exports from mscrypto.c
  */

terminal.c

@@ -1542,7 +1542,6 @@ void term_out(Terminal *term)
 		    term->logctx)
 		    logtraffic(term->logctx, (unsigned char) c, LGTYP_ASCII);
 		{
-		    extern int wcwidth(wchar_t ucs);
 		    int width = 0;
 		    if (DIRECT_CHAR(c))
 			width = 1;

wcwidth.c

@@ -8,6 +8,8 @@
 
 #include <stddef.h>
 
+#include "putty.h"
+
 struct interval {
   unsigned short first;
   unsigned short last;