Function _validHost

Validate that a hostname (for example $_SERVER['HTTP_HOST']) is safe.

Package: PHPLucidFrame\Core
Copyright: Copyright (c), PHPLucidFrame.
License: MIT License This source file is subject to the MIT license that is bundled with this source code in the file LICENSE
Author: Sithu sithu@phplucidframe.com
Located at helpers/utility_helper.php

Parameters summary
`string`	`$host`	The host name

Return value summary
`boolean`	TRUE if only containing valid characters, or FALSE otherwise.