doc: Update more docstrings to have one sentence summary as first line. Reviewed build-aux, libinterp/dldfcn, libinterp/octave-value, libinterp/parse-tree directories. * build-aux/mk-opts.pl, libinterp/dldfcn/__magick_read__.cc, libinterp/dldfcn/amd.cc, libinterp/dldfcn/audiodevinfo.cc, libinterp/dldfcn/audioread.cc, libinterp/dldfcn/ccolamd.cc, libinterp/dldfcn/chol.cc, libinterp/dldfcn/colamd.cc, libinterp/dldfcn/convhulln.cc, libinterp/dldfcn/dmperm.cc, libinterp/dldfcn/fftw.cc, libinterp/dldfcn/qr.cc, libinterp/dldfcn/symbfact.cc, libinterp/dldfcn/symrcm.cc, libinterp/octave-value/ov-base.cc, libinterp/octave-value/ov-bool-mat.cc, libinterp/octave-value/ov-cell.cc, libinterp/octave-value/ov-class.cc, libinterp/octave-value/ov-fcn-handle.cc, libinterp/octave-value/ov-fcn-inline.cc, libinterp/octave-value/ov-java.cc, libinterp/octave-value/ov-null-mat.cc, libinterp/octave-value/ov-oncleanup.cc, libinterp/octave-value/ov-range.cc, libinterp/octave-value/ov-struct.cc, libinterp/octave-value/ov-typeinfo.cc, libinterp/octave-value/ov-usr-fcn.cc, libinterp/octave-value/ov.cc, libinterp/parse-tree/lex.ll, libinterp/parse-tree/oct-parse.in.yy, libinterp/parse-tree/pt-binop.cc, libinterp/parse-tree/pt-eval.cc, libinterp/parse-tree/pt-mat.cc: doc: Update more docstrings to have one sentence summary as first line.

--- a/build-aux/mk-opts.pl	Sun May 03 17:00:11 2015 -0700
+++ b/build-aux/mk-opts.pl	Sun May 03 21:52:42 2015 -0700
@@ -232,10 +232,13 @@
   if (not defined $DOC_STRING)
     {
       $DOC_STRING = "Query or set options for the function \@code{$FCN_NAME}.\\n\\
+\\n\\
 When called with no arguments, the names of all available options and\\n\\
 their current values are displayed.\\n\\
-Given one argument, return the value of the corresponding option.\\n\\
-When called with two arguments, \@code{$OPT_FCN_NAME} set the option\\n\\
+\\n\\
+Given one argument, return the value of the option \@var{opt}.\\n\\
+\\n\\
+When called with two arguments, \@code{$OPT_FCN_NAME} sets the option\\n\\
 \@var{opt} to value \@var{val}.";
     }
 }