[plt-scheme] 205.8

The exp-tagged code in CVS for MzScheme and MrEd is now version 205.8.

The changes are minor:

 * Changed `get-argb-pixels' and `set-argb-pixels' in bitmap-dc% to
   row-major order: left to right, then top to bottom.

 * Added an optional argument to `get-face-list'. When it's 'mono, font
   faces known to be variable-width are removed from the list (under
   Windows and X with fontconfig/Xft).

 * Added `get-bitmap' and `get-bitmap-mask' to image-snip%.

 * Added `vector-immutable'.

 * Windows: fixed a bug that should have caused the save-file dialog to
   crash most of the time in DrScheme.

Matthew