Add markdown and support for it in django templates

- You can now use the 'markdown' template tag in the templates to automatically
  convert markdown to html.
Add support for collection of markdown blog posts locally

- The markdown parsing, ideas, etc. are solely adapted from the great Logr
  project, https://github.com/BrewerHimself/Logr.
- I just took that project, converted the views to django views, and placed it
  into syte as a configurable option.
- There will now be a 'blog' link in the main navigation that will show all
  available markdown articles.
    - Articles are automatically parsed from the syte/articles/ directory.  So
      you can put any markdown files in this directory and links will
      automatically be generated for these posts in the main blog page.
    - You can also include 'pages' in the syte/pages directory.  For example,
      the main blog page (/blog/ url) is a listing of all the articles by
      category and the contents of the syte/pages/FrontPage.md file.

Conflicts:

	syte/urls.py
Cleanup display of markdown articles
Update README with info for Logr/Markdown blogging support

- There is no image included for this feature yet.  As I assumed all the images
  should be consistent and from the same account.
Update README with changes to logr repo location
Merge branch 'upstream_clean' into markdown_blogging_support

Conflicts:
	README.md
	requirements.txt
	syte/views.py
Merge branch 'markdown_blogging_support' of github.com:durden/syte into markdown_blogging_support
Fix urls for markdown blogs
Resolve merge conflicts