[Kst] branches/work/kst/portto4/kst/src/libkstapp

[Mike Fenton]

SVN commit 819888 by fenton:

Update for zooming.  Remove zoom from main undo stack.  Add middle mouse undo.


 M  +83 -44    plotitem.cpp  
 M  +44 -43    plotitem.h  
 M  +5 -0      plotrenderitem.cpp