Fix EZP-22045: As a developer, I want user login to be fully handled by Symfony stack

EZP-22045: Customized login template

Fixed innerColumnSize in layout

Added « fre » siteaccess to ezdemo_frontend_group
Merge pull request #38 from ezsystems/implement_EZP-22045_userLoginSymfony

Fix EZP-22045: As a developer, I want user login to be fully handled by Symfony stack