MCludgeBitmap BitmapNumber.w,Width.w,Height.w,Memory.l ; Cludge bitmap from existing mem

Creates a new chunky Bitmap object from some existing graphics memory that may or
may not contain some chunky-format graphics. Width should be a multiple of 4.
The Memory.l base address should be aligned to a multiple of 16 bytes in memory.
If the autostencil feature of Mildred is active some new memory will also be
allocated for a stencil (not cludged). The memory you cludge a Bitmap onto
should generally be in fastram.