Fix converting $_SESSION to object (issue #4)
This version introduces multiple enhancements:

Changed and fixed problem with usage of session display markers

Details of additions/deletions below:
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Modified:   /BLUE_FRAMEWORK/packages/CORE/display_class.php
            -- Modified --
               render method, changed evaluation of _session() method
               _session method, removed default parameter, removed reading of core, merging public and display from session and fixed marker for generate

Modified:   /BLUE_FRAMEWORK/packages/CORE/module_class.php
            -- Modified --
               setSession method, removed checking variable type

Modified:   /BLUE_FRAMEWORK/modules/modul1/modul1.php
            -- Added --
               example of usage session display markers

Modified:   /BLUE_FRAMEWORK/modules/modul1/layouts/layout1.html
            -- Added --
               example of usage session display markers
               spaces between fieldset markers

Modified:   /BLUE_FRAMEWORK/modules/modul1/lang/modul1_en-GB.php
            -- Added --
               translations for example of usage session display markers

Modified:   /BLUE_FRAMEWORK/modules/modul1/lang/modul1_pl-PL.php
            -- Added --
               translations for example of usage session display markers