gcutil 1.14.2

Closes #27539.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
libtar: 1.2.20

Update libtar to 1.2.20, add build dependencies on autotools.
Point to new repository where development has been taking place.
Update libtar.rb

Remove stupid comma
libtar: add 1.2.20 bottle.