Fix exclude config

[gregarmer]

1. Remove the PostgreSQL name.
2. Use glob-style pattern matching.
3. Simplify the configuration to handle {database,schema}[.table] in a single place.
4. Give users more flexibility over excluding a table from just a single database, instead of all of them.

Example; Instead of:

"pg_exclude_dbs": ["database1", "database2"]
"pg_exclude_tables": ["table1", "django_session"]

Rather change the exclude syntax to be:

"excludes": ["database.*", "*.table", "database"]