puppet-git: use pg_die function and use one-liner tests
puppet-git: refactor pg_apply function
puppet-git: required -> missing
puppet-git: use getopt to parse command line options
puppet-git: use pg_install_missing_packages, removed pg_sanity_check
puppet-git: quote arguments
Updated man page.

The new man page lists supported distributions, has some more details
on the mode of operation of puppet-git and documents the new
command line interface.
Makefile: cleanup and removed unused (and wrong) 'all' rule.

Also added the man-preview target which previews a locally built
man page without installing it first.
puppet-git: bump version 2.0.0 because of major interface changes