Added new SubArrayInverse

Temporal name...
Addendum Utility fixed
Fixes and improvements for edge cases
Fixes and improvements for edge cases
Renamed SubArray and *Inverse functions

SubArray is now ArrayTake
SubArrayInverse is now ArraySkip
Renamed CompactArray to ArrayCompact
Rearranged Utility
menu.pet.php now generates tabindex attributes

The tabindex will helps with accessibility for those without mouse,
allowing to select the items in the menu via keyboard.

Also, this will allow CSS styling for touch support via :focus pseudo
selector.
Note: remember to remove outline with :focus {outline: none;}
New convenience PET post
Added $_ELEMENT['__parent']

$_ELEMENT['__parent'] is a copy of the parent $_ELEMENT (null if none).
allowing to access $_ELEMENT['__parent']['attributes'].
Added new default Paladio configuration sitename

This is encouraged as the standard way to tell Paladio what's the name
of the current web site or app.
New convenience PETs

needs testing