Implements a Tumblr-style "Ask Me Anything" feature to the blog, with a bit of
automation and niceness:
* The route is at `/ask`
* User can leave their name (Anonymous), email address (if they want to be
notified when you answer) and ask their question.
* The blog owner is notified about the question via email.
* The owner sees recent pending questions on the `/ask` page.
* Answering a question creates a blog entry and (if the asker left their
email) notifies the asker to check the blog at the permalink-to-be for the
new post.
Along with this feature, some changes to the blog application in
general:
* Added support for SQL databases in addition to the JsonDB system
previously in use for blogs, users, comments, etc.
* Default uses a SQLite DB at $root/.private/database.sqlite
* The "Ask Me Anything" feature uses SQLite models instead of JSON.
* Restructure the code layout:
* Rename the /internal/ package path to /src/
* Begin to consolidate models into /src/models
