Let the Column know about their ColumnSchema when instantiating
Reflect PrimaryKey on the DB structure
Move fetch() method from TableSchema to Table class
Expose primary key getted as part of the Table class
Rename PrimaryKey -> PrimaryKeySchema
Expose TableSchema creation through an interface
Make DBConnection a singleton class, expose the instance through init method
Heap alloc the table schema
Reduce include dependencies
Register all TableSchema in DBConnection
Make some TableSchema methods const
Rename Table's TableSchema instance "schema", and force it's creation when starting
Automatically create tables when DBCOnnection is intialized