Split Baobab_getUserEmissionLetterList into Baobab_getUserEmissionLetterList and Baobab_getEmissionLetterList, the new script allowing to list Emission Letters for a given list of sites.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13287 20353a03-c40f-0410-a6d1-a30d3c3de9de