Support for Game Boy Color (CGB) 

Closes #8

See merge request !16

With initial approach for scalling down the speed of other components.

Adds support for the Zelda Oracle.

Allows the transfer of data according to the specs in dma.rs.

Also removed the not needed bitwise operation.

Avoids constant comparison against wx by cmputing the initial windows index.

By avoiding many of the GBC required operations in the drawing pipeline.