extconf.rb is missing Fink paths

I prefer Fink over MacPorts and I have installed the libdevil1 package with fink.
The devil gem doesn't find it, though. I had to add -I/sw/include and -L/sw/lib to extconf.rb:
    $CFLAGS += ' -I/opt/local/include/ -I/sw/include/'
    $LDFLAGS += ' -L/opt/local/lib/ -L/sw/lib/'
Please add that to the standard extconf.rb
