Use accept_children in DataType
Use accept_children in DataType

Fixes bug 566870.

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