doc: minor updates to Class.create and Class.addMethods based on old doc.
doc: minor updates to Class.create and Class.addMethods based on old doc.

leafo/prototype,ldf7801528/prototype,ridixcr/prototype,292388900/prototype,sstephenson/prototype,ldf7801528/prototype,loduis/prototype,sdumitriu/prototype,292388900/prototype,loduis/prototype,ridixcr/prototype,sstephenson/prototype,Jiasm/prototype,ShefronYudy/prototype,ShefronYudy/prototype,sdumitriu/prototype,Jiasm/prototype,lamsieuquay/prototype,fashionsun/prototype,fashionsun/prototype,292388900/prototype,Gargaj/prototype,erpframework/prototype,ridixcr/prototype,ShefronYudy/prototype,Gargaj/prototype,sstephenson/prototype,Jiasm/prototype,baiyanghese/prototype,erpframework/prototype,lamsieuquay/prototype,Gargaj/prototype,lamsieuquay/prototype,baiyanghese/prototype,ldf7801528/prototype,leafo/prototype,erpframework/prototype,fashionsun/prototype,loduis/prototype,sdumitriu/prototype