Use the MWDebug class to display debug log back in the request.
- This removes the duplication of MWDebug::$debug and
OutputPage::$mDebugtext, so there's no need to store two times
the same text
- Removed OutputPage::debug() since it's no longer used
- Had to keep OutputPage::$mDebugtext because it's still
referenced by SemanticPageMaker extension
- Moved Skin::formatDebugHTML() to MWDebug::GetHTMLDebugLog()
and replaced the call in Skin::generateDebugHTML() to use it
- Also check $logonly before sending entries to the debug
toolbar in wfDebug(), for consistency
- Changed MWDebug::getDebugHTML() to also return the debug log
in an HTML comment if $wgDebugComments is set to true and
changed the location of this call to BaseTemplate::printTrail()
so that its result is the latest possible. This also includes
the debug toolbar.
- Removed MockOutputPage and related test cases since they are
no longer accurate
Change-Id: Ie0f389f8566457b1c938c627ed930040741ac9d9