Presence and contacts in server

configure.ac

src/Makefile.am

src/account.cpp

src/account.h

src/contact/Makefile.am

src/contact/contact.cpp

src/contact/contact.h

src/contact/presence.cpp

src/contact/presence.h

src/contact/presencestatus.h

src/iaxvoiplink.h

src/managerimpl.cpp

src/sipvoiplink.cpp

src/sipvoiplink.h

src/voiplink.cpp

src/voiplink.h