cleanup: Organize and prune configure.ac
cleanup: Organize and prune configure.ac

Gapless echo not needed, should always be build-time enabled now that we
depend on gst 0.10.26.

ixfalia/banshee,arfbtwn/banshee,GNOME/banshee,Dynalon/banshee-osx,Dynalon/banshee-osx,arfbtwn/banshee,ixfalia/banshee,Dynalon/banshee-osx,dufoli/banshee,Dynalon/banshee-osx,Dynalon/banshee-osx,babycaseny/banshee,arfbtwn/banshee,babycaseny/banshee,stsundermann/banshee,stsundermann/banshee,stsundermann/banshee,GNOME/banshee,Carbenium/banshee,babycaseny/banshee,mono-soc-2011/banshee,mono-soc-2011/banshee,Carbenium/banshee,babycaseny/banshee,GNOME/banshee,arfbtwn/banshee,arfbtwn/banshee,babycaseny/banshee,ixfalia/banshee,arfbtwn/banshee,mono-soc-2011/banshee,mono-soc-2011/banshee,Carbenium/banshee,arfbtwn/banshee,dufoli/banshee,stsundermann/banshee,mono-soc-2011/banshee,Carbenium/banshee,stsundermann/banshee,dufoli/banshee,GNOME/banshee,Dynalon/banshee-osx,Dynalon/banshee-osx,babycaseny/banshee,GNOME/banshee,stsundermann/banshee,Carbenium/banshee,babycaseny/banshee,stsundermann/banshee,dufoli/banshee,Carbenium/banshee,arfbtwn/banshee,mono-soc-2011/banshee,dufoli/banshee,mono-soc-2011/banshee,Dynalon/banshee-osx,dufoli/banshee,babycaseny/banshee,dufoli/banshee,dufoli/banshee,ixfalia/banshee,ixfalia/banshee,GNOME/banshee,ixfalia/banshee,ixfalia/banshee,GNOME/banshee,ixfalia/banshee,stsundermann/banshee,GNOME/banshee