install-chef-suse: Update bc-template-provisioner.json only when needed

We should only run bc-provisioner-json.rb if /root/.ssh/authorized_keys
exists. Otherwise, even if it doesn't exist, it will output a json file
which will be different than the original file.

Thanks to Bernhard M. Wiedemann for spotting this!
install-chef-suse: Add use_dialog to know if dialog should be called

This makes it easier to change the checks to determine if dialog should
be used or not. And one new check is that --verbose is not used: in
verbose mode, dialog was only used for the messages at the end, which is
not wanted.
Merge pull request #1836 from vuntz/install-chef-suse

install-chef-suse: Update bc-template-provisioner.json only when needed
Merge pull request #1838 from vuntz/install-chef-suse-no-verbose-dialog

install-chef-suse: Add use_dialog to know if dialog should be called
Added ability to specify admin node memory.
Merge pull request #1840 from cloudsleuth/pull-req-master-dfb690fdd3741765dc2b200a16f6185cce32880f

https://github.com/crowbar/crowbar/pull/1840

Merged by devtool for cloudsleuth
install-chef-suse: Fix comandline option handling

The unescaped '?' was catching all single letter args. So -v was not working as
expected.
Merge pull request #1841 from rhafer/master

install-chef-suse: Fix comandline option handling
Avoid double-dialog wars

The EXIT trap handler was also invoked when the
spinner got killed, which caused and erronous (duplicate)
dialog window.
Ignore errors before sanity checks

Avoid that the generic error handler triggers
when we're just outputting general debug information.