explicitly define old settings before update

so that we can be sure they have changed (or not)
Merge pull request #1675 from opf/fix/export-options-icons

Use latest icons for pdf and xls with descriptions exporting.
Add permissions for add/remove relations.
Merge pull request #1671 from opf/hotfix/no_invalid_workflow_options_on_wp_form

Hotfix/no invalid workflow options on wp form
Merge pull request #1674 from opf/fix/empty-comments-validation

Require comment text on overview/activity.
adds consistency to hash syntax
Merge remote-tracking branch 'origin/release/3.0' into dev

Conflicts:
	app/controllers/application_controller.rb
	app/views/versions/show.html.erb
	spec/controllers/account_controller_spec.rb
	spec/helpers/work_packages_helper_spec.rb
use i18n to find password settings
hide auth sources if password login is disabled and

also don't show the no-login warning for users with
external auth sources
fixed negative password example description
hide user blocking settings; link to configuration readme
updated no_login translations
use i18n in specs
Use sane default sendmail options

mikel/mail uses some standard sendmail options, which we should also
use.
They can always be overridden in configuration.yml or appropriate
environment variables.

see:
https://github.com/mikel/mail/blob/1caf1b83c112ac7df2c7d95c3aa4d5604857235c/lib/mail/network/delivery_methods/sendmail.rb#L43
Merge pull request #1677 from opf/fix/sendmail_default_options

Use sane default sendmail options

I totally know what I am doing here...
Show plugin attributes in WP overview
WIP styling comments buttons but broken quoting.
fixes the use of the word Ticket
Show/hide add/cancel buttons on comment validation.
Clean up locales for comments templates.