Make full example modules (issue #20)

This version introduces multiple enhancements:

added base construction for three example modules (generate, messages and layout)
added module to structure
some changes in templates for example

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

Added:      /BLUE_FRAMEWORK/modules/example_generate/example_generate.php
            -- Added --
                module example for basic content generating

Added:      /BLUE_FRAMEWORK/modules/example_messages/example_messages.php
            -- Added --
                module example for generating and showing messages

Added:      /BLUE_FRAMEWORK/modules/example_ajax/example_ajax.php
            -- Added --
                module example for usage ajax

Added:      /BLUE_FRAMEWORK/modules/example_layout/example_layout.php
            -- Added --
                module example for usage layouts inside of module

Modified:   /BLUE_FRAMEWORK/elements/layouts/examples/examples.html
            -- Removed --
                unused example links
Modified:   /BLUE_FRAMEWORK/cfg/lang/core_pl-PL.php
            -- Updated --
                translation fix

Modified:   /BLUE_FRAMEWORK/elements/layouts/examples/example.html
            -- Added --
                added main block for example modules

Modified:   /BLUE_FRAMEWORK/cfg/tree.xml
            -- Added --
                added some module examples to one of pages