[Theme] Make Push/PopContext methods virtual
[Theme] Make Push/PopContext methods virtual

stsundermann/banshee,arfbtwn/banshee,GNOME/banshee,GNOME/banshee,lamalex/Banshee,babycaseny/banshee,arfbtwn/banshee,petejohanson/banshee,stsundermann/banshee,ixfalia/banshee,mono-soc-2011/banshee,stsundermann/banshee,stsundermann/banshee,arfbtwn/banshee,stsundermann/banshee,GNOME/banshee,babycaseny/banshee,dufoli/banshee,arfbtwn/banshee,mono-soc-2011/banshee,allquixotic/banshee-gst-sharp-work,allquixotic/banshee-gst-sharp-work,arfbtwn/banshee,petejohanson/banshee,directhex/banshee-hacks,dufoli/banshee,ixfalia/banshee,mono-soc-2011/banshee,mono-soc-2011/banshee,Dynalon/banshee-osx,lamalex/Banshee,lamalex/Banshee,GNOME/banshee,petejohanson/banshee,Carbenium/banshee,petejohanson/banshee,ixfalia/banshee,allquixotic/banshee-gst-sharp-work,Dynalon/banshee-osx,babycaseny/banshee,babycaseny/banshee,petejohanson/banshee,babycaseny/banshee,directhex/banshee-hacks,lamalex/Banshee,arfbtwn/banshee,GNOME/banshee,allquixotic/banshee-gst-sharp-work,dufoli/banshee,Dynalon/banshee-osx,ixfalia/banshee,Carbenium/banshee,directhex/banshee-hacks,mono-soc-2011/banshee,allquixotic/banshee-gst-sharp-work,babycaseny/banshee,ixfalia/banshee,Dynalon/banshee-osx,babycaseny/banshee,lamalex/Banshee,arfbtwn/banshee,dufoli/banshee,allquixotic/banshee-gst-sharp-work,mono-soc-2011/banshee,directhex/banshee-hacks,stsundermann/banshee,ixfalia/banshee,GNOME/banshee,Carbenium/banshee,dufoli/banshee,Dynalon/banshee-osx,lamalex/Banshee,Dynalon/banshee-osx,Carbenium/banshee,dufoli/banshee,directhex/banshee-hacks,Dynalon/banshee-osx,petejohanson/banshee,ixfalia/banshee,GNOME/banshee,dufoli/banshee,directhex/banshee-hacks,babycaseny/banshee,stsundermann/banshee,Dynalon/banshee-osx,Carbenium/banshee,GNOME/banshee,mono-soc-2011/banshee,arfbtwn/banshee,Carbenium/banshee,dufoli/banshee,stsundermann/banshee,ixfalia/banshee