Update codefilter module

Note: The hope is that #502486: codefilter doesn't recognize <code> element with attributes can be included. (already referenced as child issue)

#502486: codefilter doesn't recognize <code> element with attributes has landed, so we can move forward here.

Moving tags from #2134969: blank lines / newlines are stripped out of php code in docs here to avoid duplicates.

Now deployed codefilter 7.x-1.x-dev.