handle backslash in raw string in Emacs 23
handle backslash in raw string in Emacs 23

Go-mode in Emacs 23 does not recognize a backslash followed
by a backquote as end of raw string literal, as it does not
support syntax-propertize-function which Go-mode uses to
remove special meaning from backslashes in ``.

This patch provides a fallback mechanism to do the same thing
using font-lock-syntactic-keywords, which is supported by
Emacs 23.

tjyang/go-mode.el,kimiby/go-mode.el,magastzheng/go-mode.el,dominikh/go-mode.el,codemac/go-mode.el,artemave/go-mode.el,emacsmirror/go-mode,gorakhargosh/go-mode.el,ibukanov/go-mode.el