update .gitignore.
update .gitignore.

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