new SCREEN and TextDemo release

This is another release of SCREEN and TextDemo.m. The new files
are attached in a compressed folder. Changes since the last interum
release are described below.

Best,

Allen


SCREEN.dll

- Fixed a bug where SCREEN 'OpenWindow' would not correctly initilize
the background color to the specified value.

- Changed SCREEN 'DrawText' alignment. The y coordinate now specifies
the position of the vertical baseline of the text, as on the Mac.

TextDemo.m

- Added conditionals to choose font names according to platform. The
same TextDemo.m file will now run on either platform.

- Removed SCREEN 'FillRect' call which is uneccesary now that
'OpenWindow' correctly initializes the background.

- Reverted to text coordinates in Mac version of the file, now that
font positioning rules for both platforms are the same.

- The function definition in the version released last Friday was
commented out. The line has been restored.