Make full example modules (issue #20)

This version introduces multiple enhancements:

added some templates for base examples, added translations, example page for structure and meta descriptions

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

Added:      /BLUE_FRAMEWORK/elements/layouts/examples/example.html
            -- Added --
                template for one example

Added:      /BLUE_FRAMEWORK/elements/layouts/examples/examples.html
            -- Added --
                template for all example page

Added:      /BLUE_FRAMEWORK/elements/layouts/examples/footer.html
            -- Added --
                example footer

Added:      /BLUE_FRAMEWORK/elements/layouts/examples/header.html
            -- Added --
                example header

Modified:   /BLUE_FRAMEWORK/cfg/tree.xml
            -- Added --
                added example page for page structure

Modified:   /BLUE_FRAMEWORK/cfg/meta.xml
            -- Added --
                meta elements for example page

Modified:   /BLUE_FRAMEWORK/cfg/lang/core_pl-PL.php
            -- Added --
                example polish descriptions

Modified:   /BLUE_FRAMEWORK/cfg/lang/core_en-GB.php
            -- Added --
                example english descriptions