fix calculation of widget height of filechooser
the height of filechooser is provided when creating filechooser
widget since there may be no title as in filemanger which needs
a special title widget to contain filemanger menu.
fix #1236 by opening the parent directory of last used document
Merge pull request #1242 from chrox/fix_1236

fix #1236 by opening the parent directory of last used document