[FIX] Text_Diff_Renderer and its subclasses have many methods with incompatible signatures. These raise warnings that are reported as failures when running phpunit tests. To hide the problem from phpunit, temporarily disable E_WARNING when compiling a subclass of Text_Diff_Renderer.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@47963 b456876b-0849-0410-b77d-98878d47e9d5