merge revision(s) 40504,40505,40507,40511: [Backport #7982]

	* README.EXT: Add note to warn use of %i in Exceptions [Bug #7982]

	* README.EXT: Update note from r40504, by Jeremy Evans [Bug #7982]

	* README.EXT: Copy note from r40505 for rb_sprintf() [Bug #7982]

	* README.EXT: correct method name to be used.  [Bug #7982]

	* README.EXT.ja: add notes too.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@40544 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 40478: [Backport #8334]

	* dir.c (dir_set_pos): Fix a compilation error when seekdir() is not
	  exist.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@40545 b2dd03c8-39d4-4d8f-98ff-823fe69b080e