Fix support for call to MakeProject like:

    gFile->MakeProject("./classCode/","*","RECREATE++")

Better error handling if the source file failed to be created
or if the project directory can not be created.

This fixes http://savannah.cern.ch/bugs/?83188


git-svn-id: http://root.cern.ch/svn/root/trunk@39692 27541ba8-7e3a-0410-8455-c3a389f83636