Added native support for TRAMP.

[Shigio YAMAGUCHI]

Hello everybody,
I have put new gtags.el to the repository, which natively supports TRAMP.
[http://cvs.savannah.gnu.org/viewvc/*checkout*/global/global/gtags.el]
It's working somehow, can you give it a try?

Required:
  GNU Emacs version 22 or later (Tested on version 26).
Limitations:
  gtags-visit-rootdir: Does not work.
  gtags-path-style: 'root is automatically converted to 'relative.

By the way, I still cannot pass environment variables to the remote site
using tramp mode. Can anyone please tell me how to do it?

Regards,
Shigio

-- 
Shigio YAMAGUCHI <shigio@gnu.org>
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