install-chef-suse: Add infrastructure for improved output/logging

We don't have to put everything on stdout; it would be more friendly to
only output a summary on stdout, and keep the full output in the log
file.

Ther CROWBAR_VERBOSE environment variable can be set to disable this.

Part of the code (especially the spinner) is based on similar code from
DevStack.
install-chef-suse: Add summary steps for installation process
install-chef-suse: Change log file to /var/log/crowbar/install.log

/var/log/chef/install.log is a bad name, since we don't install just
chef.
Merge pull request #1817 from vuntz/nicer-output

https://github.com/crowbar/crowbar/pull/1817

Merged by devtool for cloudsleuth