Added a Class _Con_SqliteDict which inherits SqliteDict but uses an existing Connection to initialize, it can be used for converting an existing sqlite connection to a SqliteDict connection, although it is not advised.
Added a Class SqliteTableDict which provides an interface for accessing multiple tables with a single object via nested dictionary syntax. It creates _Con_SqliteDict instances for its own connection internally to access tables.
P. S. Added .db files to .gitignore