Binding between authors and articles

Adds  binding authors to articles.
Adds ignoring of empty issues.
Adds counter for authors in current issue.

Fixes #1
A lot of enhancement and bug fixes
.\commit.txt
A lot of new functions and bug fixes

Implements
- Assessment of interest for issue
- Pager in the backend
- Author's profile page
- Comments
- Search by keyword
- Design enchantements
- Feedback
- Content fixes
- Reworked likes/unlikes for article
- Translation fixes
- Comments deleting
- Avatars
- Page headers
- Lot of small bug fixes and enchantements
Multilingual function

Main feature of this commit is implementing multilingual support into Fluent CMS
Administration panel is now divided into separated module

Lots of bugfixes and improvements for 'author' module