Add emacs CC mode style for OpenSSL

This hopefully conforms closely enough to the current code style.
Reviewed-by: NRich Salz <rsalz@openssl.org>

doc/openssl-c-indent.el

+;;; This Emacs Lisp file defines a C indentation style for OpenSSL.
+;;;
+;;; This definition is for the "CC mode" package, which is the default
+;;; mode for editing C source files in Emacs 20, not for the older
+;;; c-mode.el (which was the default in less recent releaes of Emacs 19).
+;;;
+;;; Recommended use is to add this line in your .emacs:
+;;;
+;;;   (load (expand-file-name "~/PATH/TO/openssl-c-indent.el"))
+;;;
+;;; To activate this indentation style, visit a C file, type
+;;; M-x c-set-style <RET> (or C-c . for short), and enter "eay".
+;;; To toggle the auto-newline feature of CC mode, type C-c C-a.
+;;;
+;;; If you're a OpenSSL developer, you might find it more comfortable
+;;; to have this style be permanent in your OpenSSL development
+;;; directory.  To have that, please perform this:
+;;;
+;;;    M-x add-dir-local-variable <RET> c-mode <RET> c-file-style <RET>
+;;;    "OpenSSL-II" <RET>
+;;;
+;;; A new buffer with .dir-locals.el will appear.  Save it (C-x C-s).
+;;;
+;;; For suggesting improvements, please send e-mail to levitte@openssl.org.
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Note, it could be easy to inherit from the "gnu" style...  however,
+;; one never knows if that style will change somewhere in the future,
+;; so I've chosen to copy the "gnu" style values explicitely instead
+;; and mark them with a comment.                // RLevitte 2015-08-31
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(c-add-style "OpenSSL-II"
+             '((c-basic-offset . 4)
+               (indent-tabs-mode . nil)
+               (fill-column . 78)
+               (comment-column . 33)
+               (c-comment-only-line-offset 0 . 0)            ; From "gnu" style
+               (c-hanging-braces-alist                       ; From "gnu" style
+                (substatement-open before after)             ; From "gnu" style
+                (arglist-cont-nonempty))                     ; From "gnu" style
+               (c-offsets-alist
+                (statement-block-intro . +)                  ; From "gnu" style
+                (knr-argdecl-intro . 0)
+                (knr-argdecl . 0)
+                (substatement-open . +)                      ; From "gnu" style
+                (substatement-label . 0)                     ; From "gnu" style
+                (label . 1)
+                (statement-case-open . +)                    ; From "gnu" style
+                (statement-cont . +)                         ; From "gnu" style
+                (arglist-intro . c-lineup-arglist-intro-after-paren) ; From "gnu" style
+                (arglist-close . c-lineup-arglist)           ; From "gnu" style
+                (inline-open . 0)                            ; From "gnu" style
+                (brace-list-open . +)                        ; From "gnu" style
+                (topmost-intro-cont first c-lineup-topmost-intro-cont
+                                    c-lineup-gnu-DEFUN-intro-cont) ; From "gnu" style
+                )
+               (c-special-indent-hook . c-gnu-impose-minimum) ; From "gnu" style
+               (c-block-comment-prefix . "* ")
+               ))