changed display_class options [2.11.0]

This version introduces multiple enhancements:

changed display_class options to handle language or core markers when usage in independent mode

Details of additions/deletions below:
--------------------------------------------------------------

Modified:   /BLUE_FRAMEWORK/packages/CORE/display_class.php
            -- Added --
                documentation for $_defaultOptions
            -- Updated --
                $_defaultOptions added new option clear set by default on TRUE
                _clean in clean option set on FALSE, skip cleaning templates when rendering

Modified:   /docs/template.md
            -- Added --
                usage translations in independent display_class

Modified:   /docs/module.md
            -- Added --
                description of display_class options
Merge branch 'version-2.0.1' of https://github.com/chajr/bluetree20 into version-2.0.1