Add avatar suffix, nobody*.png (as default avatars)

Fixed .gitignore some
Heads up:exclamation: There's a migration file.
just a minor point for the future: migrations shouldn't rely on model objects in case the models change before someone runs the migration. It doesn't matter for now since it's just you and me running them, but it would be important if we ever get wider adoption.

I have been setting up a sqlalchemy.Table object at the start of migrations like

```python
from sqlalchemy import (create_engine, Table, Column, String, Integer,
                        Float, Text, MetaData, select, ForeignKey,
                        bindparam, delete, and_)
from config import Configuration

engine = create_engine(Configuration.SQLALCHEMY_DATABASE_URI, echo=True)

metadata = MetaData()

settings = Table(
    'setting', metadata, 
    Column('key', String),
    Column('name', String),
    Column('value', String),
)
```