Revert "add messenger and xing buttons to ISharebuttons interface"
Revert "add messenger and xing buttons to ISharebuttons interface"

This reverts commit e8b5894837b4a928fb27fba0e4da494de8cd2364.

MurhafSousli/ng2-sharebuttons,MurhafSousli/ng2-sharebuttons,MurhafSousli/ng2-sharebuttons