pgsql: Update Emacs configuration

Update Emacs configuration

Update emacs.samples with new configuration snippets that match pgindent
et al. formatting more accurately and follow Emacs Lisp best practices
better.

Add .dir-locals.el with a subset of that configuration for casual
editing and viewing.

Reviewed-by: Dimitri Fontaine <dimitri@2ndQuadrant.fr>
Reviewed-by: Noah Misch <noah@leadboat.com>

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/5e3e8e4daaefba47ad7a8b82320531992470b5df

Modified Files
--------------
.dir-locals.el                  |   18 +++++
src/tools/editors/emacs.samples |  158 +++++++++++++--------------------------
2 files changed, 72 insertions(+), 104 deletions(-)