[e] (0) Try to clean up text where I referred to scripts that called a method, etc. Introduces the term 'incumbent script'.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=18242
Affected topics: DOM APIs, HTML, HTML Syntax and Parsing, Security, Workers

git-svn-id: http://svn.whatwg.org/webapps@7954 340c8d12-0b0e-0410-8428-c7bf67bfef74

Author:    ianh <ianh@340c8d12-0b0e-0410-8428-c7bf67bfef74>