[plt-scheme] 205.5

The exp-tagged code in CVS for MzScheme and MrEd is now version 205.5.
(The nightly build will catch up within 24 hours.)

Changes:

 * X, Mac OS: minimum size and non-stretchiness of a frame or dialog is
   enforced by the window manager --- instead of letting the user make
   the window too small or too large, then bouncing to an allowed size.

 * Added an optional argument to `begin-edit-sequence' in editor<%> to
   treat actions before and after sequence as consecutive (e.g., so
   consecutive "ctl-k"s append in the clipboard).

 * Changed the default radius for dc<%>'s draw-rounded-rectangle to
   -0.25, and added checking and a mismatch exception when the radius
   is out of range.

 * Added a hook for `(planet ...)' module paths to the standard module
   name resolver.

 * Added an optional namespace argument to most of the `namespace-...'
   primitives.

 * Added an optional argument to `peek-char' and `peek-char-or-special'
   to indicate the number of characters to skip in the input stream.

 * Fixed bugs in `module->namespace'.

Matthew