This is a Small gawk script to put all the pages= page ranges in a .bib file 
into a  uniform format, either 1234-1256 or upon request 1234-56; 12-12 always 
scrunched to just 1234; squeezes out spaces around separator; can make 
all separators one-dash or two-dashes upon request.  Very very 
conservative: probably impossible for it to actually mess up a file.