Updated feature: Added page-container for default template
Updated feature: Some improvements for headers, posts, pages and navbar
Updated feature: Set background transparent for user pages
Fixed issue: Put articli into row
Updated feature: Experemental. User avatar instead user name

Note:
1. Avarar shorter than username
2. In this case, you can place more menu items
3. Need test for different navbar font sizes
4. Experimental feature. May be canceled in next commits
Updated feature: Added post view. In the future, will be supplemented and modified in accordance with the design concept. First change - added col-md-12 class for post-page-wrapper