Documentation patch for DELIM= related to namelist

[Jerry DeLisle]

Here is some wording I am proposing to add to docs about extensions.  OK?

Jerry

Index: gfortran.texi
===================================================================
--- gfortran.texi	(revision 208303)
+++ gfortran.texi	(working copy)
@@ -1487,6 +1487,11 @@
 /
 @end smallexample

+When writing a namelist, if no DELIM= is specified, a double quote is
+used to delimit character strings.  This is done to ensure that
+namelists with character strings can be subsequently read back in
+accurately.
+
 @node X format descriptor without count field
 @subsection @code{X} format descriptor without count field