Rewrite blog admin front-end

- Streamline flows and in general throw away a lot of code
- Replace Ace Editor with Medium Editor
- Use table view on blog admin index
- Upgrade Font Awesome
- Allow editing of slug
Validate against duplicat blog post slugs
Migrate blog body from markdown to HTML

- Bring back marked package
Remove autofocus attribute

- Breaks reactivity? (https://github.com/meteor/meteor/issues/2011)
Don't escape blog post excerpt
Add image button to toolbar
'fastRender' breaks spiderable (but only on this route, on modulus?), take out for now.
Break excerpt on blockquotes too
Add reactive-table package to blog admin
Don't use session to store pageLimit, breaks IR 0.7.1. Don't need it anyway.

- Remove subscribe call in tagged route
Fix sorting on Author column. Sort by 'updatedAt' initially.
Merge branch '0.4.0'
Bump version