From Gerri:

   - improved description for the usage of PROOF_INITCMD
   - improve notification when when using dynamic environment settings
   fixes: issue on the PROOF forum (21 Dec 2007: 'change environment variables in proof')


git-svn-id: http://root.cern.ch/svn/root/trunk@21667 27541ba8-7e3a-0410-8455-c3a389f83636