Add Term::ProgressBar::IO.

This additional module supports easily updating a progressbar based on
a seekable filehandle. It also correctly handles IO::Uncompress
handles (by examining the position in the compressed filehandle
instead of the uncompressed one.)

See POD documentation in Term::ProgressBar::IO for more details.
fix the license to match Term::ProgressBar
Merge pull request #5 from dondelelcaro/term-progressbar-io

Term progressbar io