Add management and migration tools.

We can now migrate the database on changes without nuking everything,
yay! Having flask-script in place also opens up the possiblity of using
that for easier management of other stuff as well, like starting the
devserver and doing other maintenance-related scripts.
Add migrations directory for storing db migration data.

One migration have been done already, adding the 'title' attribute
for entries.
Delint and clean up object creation for stats tests.