New: Add option MAIN_MOTD_SETUPPAGE to add a content onto setup page.
Also content for MAIN_MOTD_SETUPPAGE, MAIN_MOTD_SETUPPAGE, MAIN_HOME
now accept "|langfile" into translation key to use a specific language
file.
Merge branch 'develop' of git@github.com:Dolibarr/dolibarr.git into develop