Add test for "child named after parent" bug.
Add test for "child named after parent" bug.

The added test shows that saving a node with the same name as the root
of the tree fails.

Changing Node.__cmp__() to compare by full paths should fix the
problem.

Signed-off-by: Yung-Chin Oei <fe24d7754be000e2bd0b133b4af4949f8efb911c@gmail.com>
Reviewed-by: Rob Browning <1dc5917c2adeeba13d1ef33dbb40691a1b67cc65@defaultvalue.org>

apenwarr/bup,apenwarr/bup,jbaber/bup,pombredanne/bup,ToxicFrog/bup,tjanez/bup,mhoeher/bup,apenwarr/bup,pombredanne/bup,gevaerts/bup,pombredanne/bup,mhoeher/bup,mhoeher/bup,jbaber/bup,gevaerts/bup,mhoeher/bup,pombredanne/bup,jbaber/bup,ToxicFrog/bup,tjanez/bup,jbaber/bup,mhoeher/bup,ToxicFrog/bup,tjanez/bup,jbaber/bup,jbaber/bup,gevaerts/bup,pombredanne/bup,gevaerts/bup,tjanez/bup,mhoeher/bup,pombredanne/bup,ToxicFrog/bup,gevaerts/bup,tjanez/bup,tjanez/bup,apenwarr/bup,ToxicFrog/bup