OSProcess 4.0.1:
- Added #nice: to set scheduling priority of the Squeak VM process.
- Changed #saveImageInBackground to use a better time stamped image name.
- Added #saveImageInBackgroundNicely to do a background image save at lower
  priority.
- Added #forwardSigUsr1 and #forwardSigUsr2.
- Added methods for restoring original signal handlers, e.g. #restoreSigUsr1.

OSProcessPlugin 4.0.1:
- Adds #primitiveNice for setting the scheduling priority of the Squeak
  VM process.
- Add #primitiveSigUsr1Number and #primitiveSigUsr2Number to identify the
  (platform dependent) signal numbers for SIGUSR1 and SIGUSR2.
- Changed class category to allow separate MC package names for the OSPP,
  AIO, and XDCP plugins.

The MCZ's for these packages are now being kept in SqueakSource projects,
in addition to the SARs for the SqueakMap entries.  CommandShell and
the XDCP and AIO plugins are also now kept in SqueakSource projects.

Dave