content generating error -> display_class [2.9.3] (issue #101)

This version introduces multiple enhancements:

fixed problem with strong replacing in optional content markers

Details of additions/deletions below:
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Modified:   /BLUE_FRAMEWORK/packages/CORE/display_class.php
            -- Updated --
                $_contentMarkers variable value, added # on start and end string to fix problem with missing {} in regular expression
                clean method, removed #