[e] (0) Make non-normative text more accurate.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=21173
Affected topics: Canvas

git-svn-id: http://svn.whatwg.org/webapps@7885 340c8d12-0b0e-0410-8428-c7bf67bfef74
[e] (0) Be clearer about there not being 'empty' subpaths.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=21185
Affected topics: Canvas

git-svn-id: http://svn.whatwg.org/webapps@7886 340c8d12-0b0e-0410-8428-c7bf67bfef74