alpha.v6

Sixth alpha release!

Main changes:

• redesign the entire layout! (#75)
• add new card ObjectDetails; using this new card you can change the kind of the object! (#80)

Minor changes:

• add button to cancel the change rom (#79)
• rename oam -> object (#78)
• update the default zoom (#77)
• bump many dependencies (#69)
• fix tilemap overflow; thanks @luizdepra (#14)
• fix bug when try to drag an object (#76)