Add .gitignore.
Add IDEA directory.
Fixes #16: showing not published posts to admin.
Fixes #13: showing invisible symbols in post editor.
Fixes #8: default responsive images.
Fixes #9: bugfix of excess new lines in code blocks.
Fixes #10: default stylised and responsive tables.
Fixes #12: stylized five-level headers.
Fixes #14: smart autocompleting of tags in post editor.
Fixes #15: preview in post editor.
Fixes #7: connecting to Disqus's comments threads and comments counters.
Fixes #7: replace default Disqus script for comments counters to request to Disqus API.
Fixes #7: save Disqus access parameters in Constants class.
Fixes #6: add sharign buttons.
Fixes #1: move editing, deleting and publishing buttons from control page to view of posts.
Fixes #1: correct menu; delete control page.
Fixes #1: hide post manage buttons for guests; correct site title for guests.
Fixes #1: publishing and deleting post from its view; button 'Cancel' in post editor.