Small patch for tramp.texi

[Harry P. <re...@ne...>]

This patch tries to do 3 things

Corrects a previous comment that seemed to indicate one should run
`make' from the lisp directory

Adds a small section that tries to explain in brief how to
use gnu install-info or debian install-info to create a tramp.info
entry.

Explains briefly how to byte compile the *.el files or generate 
tramp.info by hand if necessary.

A further suggestion is to include the attached dir_sample file in the
texi directory.  It would be handy for debian users, since debian's
install-info does not generate one for you like gnu install-info does.