Make full example modules (issue #20)

This version introduces multiple enhancements:

created some modules to show loadng modules to block
some changes in documentation to describe possibility to use block marker inside module template

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

Added:      /BLUE_FRAMEWORK/modules/example_blocks/example_blocks.php
            -- Added --
                base block loading example module

Added:      /BLUE_FRAMEWORK/modules/example_blocks_1/example_blocks_1.php
            -- Added --
                module loaded to block example

Added:      /BLUE_FRAMEWORK/modules/example_blocks_2/example_blocks_2.php
            -- Added --
                module loaded to block example

Added:      /BLUE_FRAMEWORK/modules/example_blocks_3/example_blocks_3.php
            -- Added --
                module loaded to block example

Added:      /BLUE_FRAMEWORK/modules/example_blocks/lang/example_blocks_en-GB.php

Added:      /BLUE_FRAMEWORK/modules/example_blocks/lang/example_blocks_pl-PL.php

Added:      /BLUE_FRAMEWORK/modules/example_blocks/layouts/index.html
            -- Added --
                base template for loading to block example

Added:      /BLUE_FRAMEWORK/modules/example_blocks_2/layouts/index.html
            -- Added --
                template loaded to block

Added:      /BLUE_FRAMEWORK/modules/example_blocks_3/layouts/index.html
            -- Added --
                template loaded to block

Added:      /BLUE_FRAMEWORK/modules/example_blocks_1/layouts/index.html
            -- Added --
                template loaded to block

Modified:   /BLUE_FRAMEWORK/cfg/lang/core_en-GB.php
            -- Updated --
                changed page description

Modified:   /BLUE_FRAMEWORK/cfg/lang/core_pl-PL.php
            -- Updated --
                changed page description

Modified:   /docs/template.md
            -- Added --
                possibility to use block marker inside module template description

Modified:   /BLUE_FRAMEWORK/cfg/tree.xml
            -- Added --
                subpage with block example