Add options for preserving extended atrributes, hard links, ACLs.

 * Fix a bug where the parent process did not wait on the child
   processes.
 * Make sure that when updating the copy progress bar, at least
   0.1 seconds have passed. This guarantees that we do not experience
   any flickering in the progress bar.

The exclude patterns should contain relative to the source paths

This reverts commit 883e57b0.
Drop the greenlet support.

Needed by new kamaki, otherwise it throughs an exception at the end.

The former is older but there are packages for it in distros like
Ubuntu.

PBS has now bocome sh.

Add progress >= 1.0.2 as install_dependency, since this is the version
that fixed the empty progress bar problem.

Also add a basic readme file.

Create a new dialog_menu module to host all the "expert mode" code.
Check the code with a new version of pep8

This dir will host help files used by snf-image-create-dialog

snf-image-creator-dialog is a dialog based version of snf-image-creator
Nothing works yet

The package is buggy and we can use pbs to do the same thing.