This protection could be implemented with a regular expression,
or using another solution (as manual parsing).
Also, when a protection detects an issue, instead of returning empty string,
it returns Void. If the value is a multiple string value, if an item is detected for an issue,
the returned multiple string value is now Void.
This abstraction will allow to return either Void, or a "corrected" value,
for instance the string value, without the detected "<script..>..</script>" text.
TODO: improve the WSF_PROTECTION_REGEXP to allow replacement strategy.
Added an utility class to get safe query and form parameters.
Added a new WSF_XSS_REQUEST to use safe parameters.
Added a filter WSF_XSS_FILTER using WSF_XSS_REQUEST.
Added test cases
Signed-off-by: jvelilla <javier.hector@gmail.com>
