Improve "whois.gtld.*" files to namespace "phpWhois\Handlers\Gtld"

[kevinoo]

Move whois.gtld.* files into the namespace phpWhois\Handlers\Gtld, using AbstractHandler class

• whois.gtld.afternic.php
• whois.gtld.alldomains.php
• whois.gtld.ascio.php
• whois.gtld.assorted.php
• whois.gtld.corporatedomains.php
• whois.gtld.directnic.php
• whois.gtld.domaindiscover.php
• whois.gtld.domainpeople.php
• whois.gtld.dotster.php
• whois.gtld.dreamhost.php
• whois.gtld.enom.php
• whois.gtld.fabulous.php
• whois.gtld.fastdomain.php
• whois.gtld.gandi.php
• whois.gtld.genericb.php
• whois.gtld.godaddy.php
• whois.gtld.iana.php
• whois.gtld.interdomain.php
• whois.gtld.itsyourdomain.php
• whois.gtld.joker.php
• whois.gtld.markmonitor.php
• whois.gtld.melbourneit.php
• whois.gtld.moniker.php
• whois.gtld.name.php
• whois.gtld.nameintel.php
• whois.gtld.namejuice.php
• whois.gtld.nameking.php
• whois.gtld.names4ever.php
• whois.gtld.namevault.php
• whois.gtld.networksolutions.php
• whois.gtld.nicco.php
• whois.gtld.nicline.php
• whois.gtld.onlinenic.php
• whois.gtld.opensrs.php
• whois.gtld.ovh.php
• whois.gtld.php
• whois.gtld.psiusa.php
• whois.gtld.publicdomainregistry.php
• whois.gtld.register.php
• whois.gtld.rrpproxy.php
• whois.gtld.schlund.php
• whois.gtld.srsplus.php
• whois.gtld.tmagnic.php
• whois.gtld.tvcorp.php
• whois.gtld.wildwestdomains.php