install-chef-suse: Check that we're running inside screen
install-chef-suse: Clean up chef database and installed barclamps

Before doing useful stuff, it's safer to start with a clean state.

One thing worth mentioning: the sed command to substitute the
machine-install password in crowbar.json is a bit more complex now, so
that it can deal with overwriting previous passwords. This quote from
http://austinmatzko.com/2008/04/26/sed-multi-line-search-and-replace/
explains it:

  sed -n '
  # if the first line copy the pattern to the hold buffer
  1h
  # if not the first line then append the pattern to the hold buffer
  1!H
  # if the last line then ...
  $ {
        # copy from the hold to the pattern buffer
        g
        # do the search and replace
        s/<h2.*</h2>/No title here/g
        # print
        p
  }
  '
barclamp_uninstall: Fix exception when removing non-existing file

If a file in filelist.txt doesn't exist, we shouldn't abort with an
exception trying to remove that file.
install-chef-suse: Rework option handling and add --verbose
add option to turn off screen
build docs for dev pull-request switch
Make smoketest cleanup work even when there is no smoketest_dir.
Add multiswitch command to dev tool.
Merge pull request #1827 from vuntz/install-chef-suse

https://github.com/crowbar/crowbar/pull/1827

Merged by devtool for VictorLowther