guestfish: Tab completion on destination paths

[Richard W.M. Jones]

I just pushed this:

http://git.et.redhat.com/?p=libguestfs.git;a=commitdiff;h=2018441f426aac5a6e...

It should provide tab completion on destination paths, partitions and
LV names, and in my limited testing it works OK.  However because this
is a major change to the interactive use of guestfish, it's possible
it will break things.  Please try it out, and if you get any sort of
failure/segfault in guestfish, let us know.

Rich.