Update CONNECTOR_API.md
Merge branch 'master' of github.com:exo-addons/cloud-drive-extension
#26 CMIS connetor (work in progress 2)
#26 CMIS connetor (work in progress 3)
#26 CMIS connetor (errormessage.gtmpl -> message.gtmpl)
#26 CMIS connetor (template method not found fixed)
#26 fixed CMIS connect window problem when second time opening shown documents instead of login page
#26 CMIS sync improved for DELETED event; UI tunning
#26 SharePoint connector and related adaptations