Add a list of contributors in README.md and remove AUTHORS file

This commit also adds AUTHORS and ChangeLog to .gitignore.
ChangeLog is only used by autoconf/automake and it has a quite
strict format. Since msgpack-c's change log is now written in
Markdown, it's difficult to follow the ChangeLog format.
So, unlike README.md, bootstrap doesn't copy CHANGELOG.md
to ChangeLog.

.gitignore

@@ -1,5 +1,7 @@
 # Files generated by the bootstrap script.
 /INSTALL
+/AUTHORS
+/ChangeLog
 /NEWS
 /README
 /ac/

AUTHORS

@@ -1,57 +0,0 @@
-Authors in no particular order, as {name, github user, email}:
-
-Original Author:
-Furuhashi Sadayuki	frsyuki		frsyuki <at> users <dot> sourceforge <dot> jp
-
-
-Takatoshi Kondo			redboltz		redboltz <at> gmail <dot> com
-Fuji Goro			gfx			gfuji <at> cpan <dot> org
-Tokuhiro Matsuno		tokuhirom		-
-Inada Naoki			methane			-
-Muga Nishizawa			muga			-
-Hideyuki Tanaka			tanakh			tanaka <dot> hideyuki <at> gmail <dot> com
-Nobuyuki Kubota			nobu-k			nobu <dot> k <dot> jp <plus> github <at> gmail <dot> com
-Makamaka Hannyaharamitu		makamaka		-
-Kazuki Ohta			kzk			kazuki <dot> ohta <at> gmail <dot> com
-Moriyoshi Koizumi		moriyoshi		mozo <at> mozo <dot> jp
-Kazuki Oikawa			kazuki			k <at> oikw <dot> org
--				advect			-
-Damian Gryski			dgryski			damian <at> gryski <dot> com
-Taro L. Saito			xerial			leo <at> xerial <dot> org
-Haneef Mubarak			haneefmubarak		-
-Thiago de Arruda		tarruda			-
-Jakob Petsovits			jpetso			jpetso <at> gmx <dot> at
-Yuto Hayamizu			hayamiz			y <dot> hayamizu <at> gmail <dot> com
-Vladimir Volodko		vvolodko		-
-Nicolas Despres			nicolasdespres		nicolas <dot> despres <at> gmail <dot> com
-Dirkjan Bussink			dbussink		d <dot> bussink <at> gmail <dot> com
-Masahiro Nakagawa		repeatedly		repeatedly <at> gmail <dot> com
-Kenichi Aramaki			firewood		-
-Kazuho Oku			kazuho			kazuho <at> natadeco <dot> co
-Naoya Watabiki			watabiki		-
-Mizuno Hiroki			mzp			mzp <at> ocaml <dot> jp
-Eric Liang			ericliang		eric <dot> l <dot> 2046 <at> gmail <dot> com
-Kouhei Sutou			kou			kou <at> clear <dash> code <dot> com
-Dror Levin			spatz			-
-Keiji Muraishi			kjim			keiji <dot> muraishi <at> gmail <dot> com
--				tbeu			-
-Hans Duedal			duedal			hd <at> onlinecity <dot> dk
-Paul Colomiets			tailhook		-
-Uli Kohler			ulikoehler		ukoehloer <at> btronik <dot> de
-Jens Alfke			snej			-
-Norio Kobota			nori0428		nori <dot> 0428 <at> gmail <dot> com
-Hong Wu				xunzhang		xunzhangthu <at> gmail <dot> com
-Drew Crawford			drewcrawford		drew <at> sealedabstract <dot> com
--				mogemimi		-
-Watson Song			watsonsong		watsonsong <at> foxmail <dot> com
-Felipe Oliveira Carvalho	philix			felipekde <at> gmail <dot> com
--				claws			-
--				xanxys			-
-Daiki Ueno			ueno			-
--				shafik			-
-Brian Shirai			brixen			brixen <at> gmail <dot> com
-Scott Prager			splinterofchaos		splinterofchaos <at> gmail <dot> com
-Brian Ketelsen			bketelsen		bketelsen <at> gmail <dot> com
-Hideyuki Takei			hideyuki		takehide22 <at> gmail <dot> com
--				bajamircea		-
--				cho45			cho45 <at> lowreal <dot> net

README.md

@@ -210,6 +210,8 @@ Contributing
 To report an issue or send a pull request, use the
 [issue tracker](https://github.com/msgpack/msgpack-c/issues).
 
+Here's the list of [great contributors](https://github.com/msgpack/msgpack-c/graphs/contributors).
+
 License
 -------