update .gitignore.
update .gitignore.

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