Tidy up "vpn_openvpn_client.php" XHTML

Add CDATA section to SCRIPTS
Add SUMMARY to TABLES
Remove Unordered List for tabs
Close BR, INPUT and IMG tags and ALT to IMG
Move NOWRAP into CLASS statement
Deprecate Ampersand in Anchor tags
Move TFOOT between THEAD and TBODY (quirk of HTML!)
Add dummy row to end of TBODY but don't display it