Don't use wxMkDir, it shows stupid error messages

src/util/file_utils.cpp

@@ -113,6 +113,14 @@ time_t file_modified_time(const String& path) {
 
 // ----------------------------------------------------------------------------- : Directories
 
+bool create_directory(const String& path) {
+  #if defined(__WX_MSW__)
+    return _wmkdir(path.fn_str()) == 0;
+  #else
+    return mkdir(path.fn_str()) == 0;
+  #endif
+}
+
 bool create_parent_dirs(const String& file) {
   for (size_t pos = file.find_first_of(_("\\/"), 1) ;
        pos != String::npos ;

src/util/file_utils.hpp

@@ -45,6 +45,8 @@ time_t file_modified_time(const String& name);
 
 // ----------------------------------------------------------------------------- : Removing and renaming
 
+bool create_directory(const String& path);
+
 /// Ensure that the parent directories of the given filename exist
 bool create_parent_dirs(const String& file);
 

src/util/io/package.cpp

@@ -401,7 +401,7 @@ void Package::openZipfile() {
 
 void Package::saveToDirectory(const String& saveAs, bool remove_unused, bool is_copy) {
   // create directory?
-  wxMkdir(saveAs);
+  create_directory(saveAs);
   // write to a directory
   VCSP vcs = getVCS();
   FOR_EACH(f, files) {