add file reset_install.sh
change symfony/icu version for compatibility
Completed mailing templates management
Merge branch 'master' of https://github.com/thelia/thelia into coupon

# By Manuel Raynaud (2) and franck (1)
# Via franck
* 'master' of https://github.com/thelia/thelia:
  Completed mailing templates management
  change symfony/icu version for compatibility
  add file reset_install.sh

Conflicts:
	composer.json
	core/lib/Thelia/Config/Resources/config.xml
	core/lib/Thelia/Model/Map/CouponI18nTableMap.php
	install/thelia.sql
	local/config/schema.xml
	reset_install.sh