Update HTML in  "include" files

Udated the DOCTYPE to make it W3C standard/compliant.

Moved "sorttable.js", "ticker.js" and the "antiClickJack style" from
"fbegin.inc" and place them in "head.inc" (where they belong), this may
also help the Widescreen package to work.

Close BR, INPUT and IMG tags properly, update IMG tags with "alt" and
update TABLE tags with "summary".

Updated the SCRIPT and STYLE with proper CDATA sections.

Updated LINK with the correct types.
Update HTML code in "include" files

Close BR, INPUT and IMG tabs, update the IMG tags with "alt" and update
the TABLE tags with "summary".

Update SCRIPT with proper CDATA sections.
Merge pull request #389 from ExolonDX/branch_06

Update HTML code in "include" files
Only include files that actually end in .inc, otherwise patching can lead to errors since .inc.orig patched the old test.
Make gen_subnetv6 return a compressed form IPv6 address/net representation. This removes some issues reported during Ticket #2746 and solve the issue on some cases
Correct name of function call and use directly its return value as its boolean as needed. Also correct the function to be more readble and put a note for v4 checks that might be needed
Cosmetic change, s/manager/Manager/ to keep make it consistent with other entries
Merge pull request #387 from ExolonDX/branch_02

Update HTML code in  "include" files
Value in attributes should be lower case

Value in the "method" attribute should be lower case
Merge pull request #390 from ExolonDX/branch_05

Value in attributes should be lower case
Remove escaped apostrophe
Indent and whitespaces changes
Indent and whitespaces changes
Implement privilege for allowing login through CP

- The feature is optional, on by default for new zones, off for current
  ones when upgrading

It should fix #1010
Merge pull request #391 from ExolonDX/branch_06

Remove escaped apostrophe
This is quoted that way because it's passed in javascript. If another better way to quote it works, feel free to change it back, but test the fix first and make sure aliases still display in the firewall rule list.
Fix quoting.
Don't generate a PHP error for an unfetchable XML file.
Require util.inc necessary for sigkillbypid()
Add a line break to move this text to the next line. It was stuck after another field and easy to miss.