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/libinterp/octave-value/ov-fcn-handle.cc	Sun May 03 17:00:11 2015 -0700
+++ b/libinterp/octave-value/ov-fcn-handle.cc	Sun May 03 21:52:42 2015 -0700
@@ -1676,7 +1676,7 @@
 Return a structure containing information about the function handle\n\
 @var{fcn_handle}.\n\
 \n\
-The structure @var{s} always contains these 3 fields:\n\
+The structure @var{s} always contains these three fields:\n\
 \n\
 @table @asis\n\
 @item function\n\
@@ -1811,8 +1811,8 @@
 DEFUN (func2str, args, ,
        "-*- texinfo -*-\n\
 @deftypefn {Built-in Function} {} func2str (@var{fcn_handle})\n\
-Return a string containing the name of the function referenced by\n\
-the function handle @var{fcn_handle}.\n\
+Return a string containing the name of the function referenced by the\n\
+function handle @var{fcn_handle}.\n\
 @seealso{str2func, functions}\n\
 @end deftypefn")
 {
@@ -1851,6 +1851,7 @@
 @deftypefn  {Built-in Function} {} str2func (@var{fcn_name})\n\
 @deftypefnx {Built-in Function} {} str2func (@var{fcn_name}, \"global\")\n\
 Return a function handle constructed from the string @var{fcn_name}.\n\
+\n\
 If the optional @qcode{\"global\"} argument is passed, locally visible\n\
 functions are ignored in the lookup.\n\
 @seealso{func2str, inline}\n\