I modify the CTCoreFolder.m in order to support the chinese path name(UTF8String)

In order to support the chinese path name for moveMessageWithUID:toPath: and  copyMessageWithUID:toPath:.I add the codes into the two methods as follows:
   - (BOOL)copyMessageWithUID:(NSUInteger)uid toPath:(NSString *)path {
    BOOL success = [self connect];
    if (!success) {
        return NO;
    }
//    const char *mbPath = [path cStringUsingEncoding:NSUTF8StringEncoding];
    char mbPath[MAX_PATH_SIZE];
    [self getUTF7String:mbPath fromString:path];//convert UTF8 into UTF7
    int err = mailsession_copy_message([self folderSession], uid, mbPath);
    if (err != MAIL_NO_ERROR) {
        self.lastError = MailCoreCreateErrorFromIMAPCode(err);
        return NO;
    }
    return YES;
}

- (BOOL)moveMessageWithUID:(NSUInteger)uid toPath:(NSString *)path {
    BOOL success = [self connect];
    if (!success) {
        return NO;
    }
//    const char *mbPath = [path cStringUsingEncoding:NSUTF8StringEncoding];
    char mbPath[MAX_PATH_SIZE];
    [self getUTF7String:mbPath fromString:path];//convert UTF8 into UTF7
    int err = mailsession_move_message([self folderSession], uid, mbPath);
    if (err != MAIL_NO_ERROR) {
        self.lastError = MailCoreCreateErrorFromIMAPCode(err);
        return NO;
    }
    return YES;
}