added a Content-Description to the signature part - part of a merge from the 1-0 branch.
added a Content-Description to the signature part - part of a merge from the 1-0 branch.

Distrotech/evolution-data-server,Distrotech/evolution-data-server,gcampax/evolution-data-server,matzipan/evolution-data-server,tintou/evolution-data-server,gcampax/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,matzipan/evolution-data-server,gcampax/evolution-data-server,Distrotech/evolution-data-server,matzipan/evolution-data-server,matzipan/evolution-data-server,gcampax/evolution-data-server,matzipan/evolution-data-server,tintou/evolution-data-server