Check signature of overriding methods for async
Check signature of overriding methods for async

Signed-off-by: Frederik 'playya' Sdun <c4ff3c6b10cf37109f879dd01b9310acdd816534@googlemail.com>

playya/vala,rvu95/vala,jessevdk/vala,themiwi/vala,flobrosch/vala-fixes,playya/vala,phako/vala,Distrotech/vala,tjol/vala-tjol,kamanashisroy/aroop,spidermonkdust/vala,jessevdk/vala,Distrotech/vala,spidermonkdust/vala,themiwi/vala,GNOME/vala,severinh/vala,lovebug356/vala,Jc2k/vala,frida/vala,lovebug356/vala,playya/vala,GNOME/vala,flobrosch/vala-fixes,spidermonkdust/vala,tjol/vala-tjol,flobrosch/vala-fixes,GNOME/vala,kamanashisroy/aroop,Jc2k/vala,kamanashisroy/aroop,rvu95/vala,jessevdk/vala,frida/vala,tjol/vala-tjol,frida/vala,frida/vala,Distrotech/vala,rvu95/vala,frida/vala,GNOME/vala,themiwi/vala,severinh/vala,severinh/vala,phako/vala,xdave/pvala