bson-to-json: allow specifying "-" for STDIN.
bson-to-json: allow specifying "-" for STDIN.

remicollet/libbson,mongodbinc-interns/libbson,Convey-Compliance/libbson,ksuarz/libbson,rayyang2000/libbson,bjori/libbson,jqk6/libbson,rcsanchez97/libbson,Convey-Compliance/libbson,4Second2None/libbson_tmp,mongodbinc-interns/libbson,bjori/libbson,mongodb/libbson,4Second2None/libbson_tmp,derickr/libbson,bjori/libbson,Machyne/libbson,jqk6/libbson,mapr/libbson,paulmelnikow/libbson,paulmelnikow/libbson,derickr/libbson,Machyne/libbson,paulmelnikow/libbson,derickr/libbson,rayyang2000/libbson,rcsanchez97/libbson,ajdavis/libbson,ksuarz/libbson,ksuarz/libbson,paulmelnikow/libbson,rayyang2000/libbson,remicollet/libbson,derickr/libbson,mapr/libbson,alexeyvo/libbson,4Second2None/libbson_tmp,4Second2None/libbson_tmp,mapr/libbson,mongodbinc-interns/libbson,remicollet/libbson,jqk6/libbson,paulmelnikow/libbson,rayyang2000/libbson,mongodbinc-interns/libbson,alexeyvo/libbson,remicollet/libbson,ajdavis/libbson,Machyne/libbson,mongodb/libbson,jqk6/libbson,Machyne/libbson,alexeyvo/libbson,mongodb/libbson,ajdavis/libbson,rcsanchez97/libbson,Convey-Compliance/libbson