Refactored to not pass an always_unzip option to

zc.buildout.easy_install.install if the user didn't use an unzip
option. This is to allow defaults set at the buildout level to be honored.


git-svn-id: http://svn.zope.org/repos/main/zc.buildout/trunk@88548 62d5b8a3-27da-0310-9561-8e5933582275