dump: Optimize indenting
dump: Optimize indenting

Don't alloca() a whitespace buffer and fill it with spaces in each
call to dump_indent. Instead, use a static whitespace buffer.

As a bonus, this saves the use of poorly portable alloca().

npmccallum/jansson,AmesianX/jansson,janetuk/jansson,slackner/jansson,simonfojtu/FireSight,rogerz/jansson,liu3tao/jansson,Vorne/jansson,firepick1/jansson,firepick1/jansson,wirebirdlabs/featherweight-jansson,yahoo/ygloo-external-jansson,janetuk/jansson,gameclosure/jansson,markalanj/jansson,npmccallum/jansson,attie/jansson,wirebirdlabs/featherweight-jansson,AmesianX/jansson,Vorne/jansson,bstarynk/jansson,akheron/jansson-debian,janetuk/jansson,OlehKulykov/jansson,firepick-delta/FireSight,firepick-delta/FireSight,akheron/jansson-debian,Mephistophiles/jansson,Mephistophiles/jansson,janetuk/jansson,attie/jansson,bstarynk/jansson,chrullrich/jansson,akheron/jansson-debian,rogerz/jansson,simonfojtu/FireSight,chrullrich/jansson,akheron/jansson,markalanj/jansson,slackner/jansson,yahoo/ygloo-external-jansson,rogerz/jansson,akheron/jansson,firepick1/jansson,bstarynk/jansson,akheron/jansson,firepick1/FireSight,akheron/jansson-debian,gameclosure/jansson,gameclosure/jansson,yahoo/ygloo-external-jansson,markalanj/jansson,firepick1/FireSight,OlehKulykov/jansson,liu3tao/jansson,simonfojtu/FireSight,firepick1/FireSight,yahoo/ygloo-external-jansson,firepick-delta/FireSight,rogerz/jansson