* complax.c: [DOC] Document number conversion of `nil` by @skade [fix GH-570] [ci skip]

	* object.c, rational.c: ditto.
	* object.c: fix document of Kernel.Stirng by @suzukaze
	  [fix GH-743][ci skip]

	* object.c (Module#const_defined?): [DOC] Revise the documentation.
	  Patch by Xavier Noria.
	  [Fixes GH-754] https://github.com/ruby/ruby/pull/754

	* object.c: [DOC] Revise documentation by Marcus Stollsteimer at
	  [ruby-core:66368].  [Bug #10526]
	  * #inspect: be more specific about generated string, remove
	    obsolete example.
	  * #nil?: use code examples instead of different call-seq's.
	  * #tap: clarify what is yielded.
	  * Integer(): be more specific about to_int and to_i, remove
	    reference to Ruby 1.8.
	  * Array(): fix error.
	  * Class: fix variable name style and indentation in example.
	  * improve consistency, fix typos and formatting.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@49448 b2dd03c8-39d4-4d8f-98ff-823fe69b080e