more sensible mailer option defaults

Conflicts:
	app/mailers/base_mailer.rb
	config/app_config.yml.SAMPLE
	spec/app_config.yml

Conflicts:
	config/app_config.yml.SAMPLE
	spec/app_config.yml
update strings from localeapp

Conflicts:
	config/locales/fr.yml
fix more sensible mailer option defaults
use fixed from address, also for messages

necessary to comply to DMARC
use mailer base class
export + encoding fix (ruby 1.9.3)
allow to put foodcoop config in database
add foodcoop configuration screen
don't fail in foodsoft_config without database,

and use proper config defaults so that configuration editing has
sensible default values
hide protected keys from config
let plugins define their own foodcoop-config defaults
allow to specify (un)checked values for config boolean

Conflicts:
	app/helpers/admin/configs_helper.rb
allow protected keys to be set/unset + config_db tests
fix deprecation warning
specify timezone in configuration (closes foodcoops#282)
make config_db work on Rails 3
add foodcoop-adam-specific config_db screens
Add membership options to configuration screen
protect shared supplier assets path
finish signup config screen + show signup only    when possible