Fix minor inconsistencies

@@ -335,7 +335,7 @@ get_content_type (mu_header_t hdr, mu_content_type_t *ctp, char const *dfl)
   int rc;
   char *buffer = NULL;
   
-  rc = mu_header_aget_value (hdr, MU_HEADER_CONTENT_TYPE, &buffer);
+  rc = mu_header_aget_value_unfold (hdr, MU_HEADER_CONTENT_TYPE, &buffer);
   if (rc == 0)
     {
       rc = mu_content_type_parse (buffer, ctp);

+/* Content-Type (RFC 2045) parser for GNU Mailutils
+   Copyright (C) 2016 Free Software Foundation, Inc.
+
+   GNU Mailutils is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   GNU Mailutils is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>. */
+
 #if HAVE_CONFIG_H
 # include <config.h>
 #endif
@@ -53,6 +69,10 @@ parse_type (const char *input, mu_content_type_t ct)
   return parse_subtype (input + i + 1, ct);
 }
 
+static char tspecials[] = "()<>@,;:\\\"/[]?=";
+
+#define ISTOKEN(c) ((unsigned char)(c) > ' ' && !strchr (tspecials, c))
+
 static int
 parse_subtype (const char *input, mu_content_type_t ct)
 {
@@ -60,8 +80,7 @@ parse_subtype (const char *input, mu_content_type_t ct)
 
   for (i = 0; !(input[i] == 0 || input[i] == ';'); i++)
     {
-      if (input[i] == 0
-	  || !(mu_isalnum (input[i]) || input[i] == '-' || input[i] == '_'))
+      if (!ISTOKEN (input[i]))
 	return MU_ERR_PARSE;
     }
   ct->subtype = malloc (i);
@@ -86,7 +105,7 @@ parse_params (const char *input, mu_content_type_t ct)
   
   while (*input == ';')
     {
-      input = mu_str_skip_class (input + 1, MU_CTYPE_BLANK);
+      input = mu_str_skip_class (input + 1, MU_CTYPE_SPACE);
       rc = parse_param (&input, ct);
       if (rc)
 	return rc;
@@ -94,7 +113,7 @@ parse_params (const char *input, mu_content_type_t ct)
 
   if (*input)
     {
-      input = mu_str_skip_class (input, MU_CTYPE_BLANK);
+      input = mu_str_skip_class (input, MU_CTYPE_SPACE);
       ct->trailer = strdup (input);
       if (!ct->trailer)
 	return ENOMEM;
@@ -103,10 +122,6 @@ parse_params (const char *input, mu_content_type_t ct)
   return rc;
 }
 
-static char tspecials[] = "()<>@,;:\\\"/[]?=";
-
-#define ISTOKEN(c) ((unsigned char)(c) > ' ' && !strchr (tspecials, c))
-
 static int
 parse_param (const char **input_ptr, mu_content_type_t ct)
 {
@@ -205,7 +220,7 @@ mu_content_type_parse (const char *input, mu_content_type_t *retct)
   if (!ct)
     return errno;
 
-  rc = parse_type (mu_str_skip_class (input, MU_CTYPE_BLANK), ct);
+  rc = parse_type (mu_str_skip_class (input, MU_CTYPE_SPACE), ct);
   if (rc)
     mu_content_type_destroy (&ct);
   else