D-Bus: Support DBus.signature attribute for struct fields
D-Bus: Support DBus.signature attribute for struct fields

Fixes bug 645528.

tjol/vala-tjol,spidermonkdust/vala,xdave/pvala,GNOME/vala,flobrosch/vala-fixes,rvu95/vala,kamanashisroy/aroop,GNOME/vala,Distrotech/vala,jessevdk/vala,flobrosch/vala-fixes,playya/vala,tjol/vala-tjol,rvu95/vala,Distrotech/vala,frida/vala,severinh/vala,rvu95/vala,jessevdk/vala,kamanashisroy/aroop,jessevdk/vala,frida/vala,frida/vala,severinh/vala,spidermonkdust/vala,playya/vala,tjol/vala-tjol,spidermonkdust/vala,frida/vala,flobrosch/vala-fixes,frida/vala,Distrotech/vala,kamanashisroy/aroop,playya/vala,GNOME/vala,severinh/vala,GNOME/vala