fix #10 Update FSF address
fix #2 update various documentations for debian packaging
a potential improvement for #9 font fractional pixels causes spacing errors
Fix missing cleanup for temporary history files

QTermWidget only add the TerminalDisplay to qt's owner hierarchy for
automatic cleanup. With each new tab a new Session object will be
created and but never deleted (which would cleanup internally the
history files).

This bugfix simple adds to each Session's parent relationship the
corresponding QTermWidget.
Merge pull request #15 from ruuns/master

Fix missing cleanup for temporary history files
Add a method for get working directory in class QTermWidget
Current Working Directory for linux. Part of #8. More implementations welcomed...