Requests for comment/Ditch crappy API formats

Here's the breakdown of API formats requested by users during one day in June 2014: 375079448	json 34750831	xml 13068687	php 243625	xmlfm 71337	txt 62549	jsonfm 41158	text/x-wiki 34458	dbg 24460	yaml 7532	txtfm 34	yamlfm 31	dbgfm 28	none 25	rawfm 23	dump 22	phpfm 22	wddxfm 22	dumpfm 18	wddx 4	html 4	jsonf 3	jsonp 3	j 2	atom 2	raw 2	text 2	csv 2	PHP%20print_r 1	wdxfm 1	default 1	pjson 1	xhtml 1	XML 1	plain 1	htmlfm 1	yamfm 1	xml%27 1	xm%20l 1	js 1	jsonaction%3Dquery 1	json%0D%0A 1	xml%27,%200,%20true 1	xml%27,0,true 1	jaon 1	xmuslfm

Problem
Some formats shouldn't have been added in the first place, now they're largely unused.