Add temporary post to test git-push deploy.

_posts/2014-09-21-test-post.md
	-Add a bare-bones post to test whether the site's server will
	execute its post-receive hook.
Clean up formatting in plugin files.

_plugins/(tag-cloud, tocGenerator).rb
	-Convert soft-tabs to hard-tabs.
	-Add leading author-attribution comments.
	-Fix misalignment in `tocGenerator.rb`.
Move external plugins to own directory, add README.

_plugins/( -> external_plugins/)(tag-cloud, tocGenerator).rb
	-Move external plugin files to own `external_plugins` directory.

_plugins/external_plugins/README.md
	-Add a README clarifying that the plugins came from outside
	sources, but needed local modifications.
Merge branch 'refactor/plugins'

_plugins/external_plugins
	-Move external plugin files in `_plugins/` to own
	`external_plugins/` directory.