limit rss feed for some services that have limits (like feedburner)

Conflicts:
	app/controllers/refinery/blog/posts_controller.rb
add max_results feature to readme

Conflicts:
	readme.md
Move down "Additional Features" section in readme.

This also adds "More Information" section.

Conflicts:
	readme.md
Need to call html_safe on unsafe string before concatenating it to safe string.

Read explanation at
https://github.com/refinery/refinerycms-blog/issues/325#issuecomment-198
07945.

Closes #325.

Conflicts:
	app/views/refinery/blog/posts/_nav.html.erb
Increment version to 2.0.5 as it's not 2.0.4
Updated Gemfile to reduce unused dependencies.
Added MIT license to gemspec.
Fix 1.8.7 CI error: Gem::InstallError: nokogiri requires Ruby version >= 1.9.2
Merge branch '2-0-stable' of https://github.com/refinery/refinerycms-blog into 2-0-stable

Conflicts:
	app/controllers/refinery/blog/posts_controller.rb
	spec/controllers/refinery/blog/posts_controller_spec.rb
fix auto completion of tags
Merge branch 'tags_fix' into 2-0-stable