Add language switcher backend logic

ajax.php

classes/editor_ajax.php

classes/editor_framework.php

classes/framework.php

db/install.xml

db/upgrade.php

lang/ca/hvp.php

lang/de/hvp.php

lang/en/hvp.php

lang/es/hvp.php

lang/fr/hvp.php

lang/he/hvp.php

lang/no/hvp.php

lang/pt/hvp.php

lang/pt_br/hvp.php

lang/tr/hvp.php

locallib.php

version.php