Generally saying, all memory leaks I currently observe on a test load of
a single PerDoc topic of Foswiki::Exception documentation are related to
use of global variables.

Imported Devel::Leak::Object module and adapted it to support
Foswiki::Object infrastructure to get correct locations of where objects
were created and to keep stacktraces for easy tracking down of leakage
causes. Because it's primarily a test-related module included it into
UnitTestContrib unfrastructure and called it Unit::Leak::Object.

- foswiki_debug.psgi tries to make use of Unit::Leak::Object first and
then falls back to Devel::Leak::Object if failed.

- QUERY macro object is now using attribute evalParser instead of a
global variable $evalParser.

- Got rid of BEGIN block in Query::Node.

- Added method __orig to Foswiki::Object which locates the exact point
where object was created bypassing ::new and ::create methods.

- JsonRpcContrib cleans up $SERVER global variable upon destruction.

- Changed the way it checks if module has been loaded.

- Improved error hadnling when loading fails.

- Few documentation adjustments.

Added documentation for method clone().

It was a hard to extend mess. Reimplemented using simple lexical parsing
based on Perl's regexps. It is now much easier to adapt it to the new
OO terminology and constructs.

The old behaviour can be returned back by setting
Foswiki::IncludeHandlers::doc::USER_LEXICAL_PARSER constant to 0. Could
also be controlled by some LSC value but I see no point in this.

- Slightly improved error handling by INCLUDE macro.

…nvironment variable.

…to Item14152

* commit 'f798fe266f44c16bd49cf3f8d61eab0e42a58688':
  Item13897: Turn on memorly leak detection only by FOSWIKI_CHECKLEAK environment variable.
  Item13897: Experimental rewrite of Foswiki::IncludeHandlers::doc
  Item13897: Minor documentation fixes.
  Item13897: Fixed loosing of cloned __orig_ attributes.
  Item13897: Fixed a problem with disapperaring $SERVER.
  Item13897: Fixed load_package() for more reliability
  Item13897: Fixed few memory leaks.