[mizar] New Mizar version 7.8.03

[Adam Grabowski <adam@math.uwb.edu.pl>]

  Dear Mizar Users,
  this is to inform you that the new release of the Mizar Mathematical
Library (4.75.958) is now available together with the system binaries 
(ver. 7.8.03) for all supported platforms. Underlying links can be find
on our main home page (http://mizar.uwb.edu.pl and http://mizar.org).
  The MML was cleaned under standard review software; observe that
a new EMM (Encyclopedia of Mathematics in Mizar) item is available.
XBOOLEAN is devoted to the arithmetic of boolean values.
  Regards,
  Adam Grabowski
  Library Committee of the Association of Mizar Users