ファイル、フォルダ削除
-(BOOL)removeFileByPath:(NSString*)filePath
{
    NSString* path=[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
    path=[path stringByAppendingPathComponent:filePath];
    NSFileManager *fm = [NSFileManager defaultManager];
    NSError *error=nil;
    BOOL flg=[fm fileExistsAtPath:path];
    if (!flg) {
        NSLog(@"no file");
        return YES;
    }
    
    return [fm removeItemAtPath:path error:&error];
}