Give article title a Unique sql constraint.

[hgzimmerman]

• Give unique title constraint.
• Create a reversible function that turns a title into a valid url string.
• Allow querying of database for articles via title in addition to by id.

[hgzimmerman]

It occurred to me after creating this issue that URL slug generating functions are not typically reversible.
Either some intense validation needs to be created to prevent the entry of title names that can't be reversible or the title is used to generate another column that will contain the slug.

I'm leaning towards the latter.

[hgzimmerman]

I have slug included as a dependency now. Now I need to store the slug in the DB.