Added sidebar to blog and project pages

Added sidebar to blog/projects tag, which shows all available tag links,
and in the case of blog, it shows archive links as well.

Added:
* views/template/side_bar_v.php ~ sidebar view

Changes:
* controllers/blog.php ~ added functionality for filtering by archive
date, as well as populating the sidebar data
* controllers/project.php ~ added functionality for populating the
sidebar data
* models/blogpost_m.php ~ added functionality for retrieving and
counting blog posts by date criteria. Also added functionality for
getting list of archive months, as well as distinct tags, for the
sidebar.
* models/project_m.php ~ added functionality for getting distinct tag
list for sidebar
* views/main_layout_v.php ~ Added code for loading the sidebar
* css/main.css ~ Added sidebar container styling