Added the following features:
1. Added Grid layout in PyQT4
2. Added window and code for dumping text and xml files.
3. Added a new button "Dump". Files that are not xml,txtor pdf are
saved in /tmp directory with a message printed on the textEdit box.
3. PDF files are evince'ed.
Fiwalk generates the dfxml file if not provided on command line.
Merge pull request #56 from sunithamisra/master

Added the following features: