editors: specify fill column

Let's be a bit more precise with the editor configuration and specify a higher fill column of 119. This isn't as emacs'
default of 70, but also not particularly high on today's screens.

While we are at it, also set a couple of other emacs C coding style variables.

.dir-locals.el

@@ -3,5 +3,11 @@
 ; Mode can be nil, which gives default values.
 
 ((nil . ((indent-tabs-mode . nil)
-         (tab-width . 8)))
-)
+         (tab-width . 8)
+         (fill-column . 119)))
+ (c-mode . ((c-basic-offset . 8)
+            (eval . (c-set-offset 'substatement-open 0))
+            (eval . (c-set-offset 'statement-case-open 0))
+            (eval . (c-set-offset 'case-label 0))
+            (eval . (c-set-offset 'arglist-intro '++))
+            (eval . (c-set-offset 'arglist-close 0)))))

.vimrc

@@ -7,3 +7,4 @@ set tabstop=8
 set shiftwidth=8
 set expandtab
 set makeprg=GCC_COLORS=\ make
+set tw=119