Tidy up "system_authservers.php" XHTML

Add CDATA sections to SCRIPT tags
Update HTML boolean operators
Close INPUT tags
Move TFOOT between THEAD and TBODY, this is a "quirk" of HTML
Deprecate the ampersand in ANCHOR tags
Add missing closing HTML tag
Merge pull request #542 from ExolonDX/branch_07

Tidy up "system_authservers.php" XHTML