pull up r19859 from trunk

pull up r19859 from trunk

 r19859@cathode-dark-space:  jaltman | 2007-08-24 10:37:07 -0400
 ticket: new
 subject: NIM: Handle WM_PAINT messages without update regions
 component: windows

 It is possible to receive a WM_PAINT message in Windows without there
 being an update region.  For example, this can be caused by someone
 calling RedrawWindow() with the RDW_INTERNALPAINT flag set.  In this
 case, GetUpdateRect() will indicate that there is no update region and
 calling BeginPaint()/EndPaint() results in incorrect behavior.

 The credentials window in Network Identity Manager needs to perform
 special handling for this case by obtaining a proper device context
 and completing the drawing operation.

ticket: 5680
version_fixed: 1.6.3

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-6@19994 dc483132-0cff-0310-8789-dd5450dbe970