jamiaccount: extract code related to sync

src/jamidht/CMakeLists.txt

src/jamidht/Makefile.am

src/jamidht/jamiaccount.cpp

src/jamidht/jamiaccount.h

src/jamidht/sync_channel_handler.cpp

src/jamidht/sync_channel_handler.h

src/jamidht/sync_module.cpp

src/jamidht/sync_module.h

src/uri.cpp

src/uri.h