[build] Ignore letter suffixes in autotools versions
[build] Ignore letter suffixes in autotools versions

Filter out letter suffixes in the version number reported by the autools
stuff. Fixes a harmless error message while running autogen.sh with
libtool 2.2.6b.

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