Merge branch 'ks/rfc2047-one-char-at-a-time' into maint

When "format-patch" quoted a non-ascii strings on the header files,
it incorrectly applied rfc2047 and chopped a single character in the
middle of it.

* ks/rfc2047-one-char-at-a-time:
  format-patch: RFC 2047 says multi-octet character may not be split

utf8.h

@@ -22,4 +22,6 @@ char *reencode_string(const char *in, const char *out_encoding, const char *in_e
 #define reencode_string(a,b,c) NULL
 #endif
 
+int mbs_chrlen(const char **text, size_t *remainder_p, const char *encoding);
+
 #endif