bitmap Image integration

[hilaire]

The user should be able to drag and drop a bitmap image in DrGeo canvas.

The image should then scale and move when the canvas is updated.

[hilaire (hilaire-fernandes)]

- encapsulate bitmap in a DrGBitmapMathItem, DrGBitmapCostume and DrGBitmapMorph
- when unlocked, user can move around the bitmap item when in select mode
- when user tap on the DrGBitmapMorph instance, 4 grips appear at the corners to resize OR resize can be achieve when dragging a corner?
- xml saved done in JPEG encoded stream

[hilaire (hilaire-fernandes)]

When a picture is dragged from the host desktop in the DrGeo canvas, the picture is encapsulated in a DrGBitmapItem and added in the DrGeo's items factory and canvas.