fix bug in PersistFileDialog where, on second use, it would erroneously change dir to the found dir, and stay there; not good;  this goes back to before when this module was put into pytools in 2008
fix bug in PersistFileDialog where, on second use, it would erroneously change dir to the found dir, and stay there; not good;  this goes back to before when this module was put into pytools in 2008

git-svn-id: 6d9763a5a770351123389058c013888add577529@20343 fe389314-cf27-0410-b35b-8c050e845b92

spacetelescope/stsci.tools