doc: Use XREF as anchor prefix in documentation for clearer results in Info viewer. Correctly use @xref, @pxref, @ref macros in documentation. * doc/interpreter/arith.txi, doc/interpreter/basics.txi, doc/interpreter/container.txi, doc/interpreter/debug.txi, doc/interpreter/diagperm.txi, doc/interpreter/eval.txi, doc/interpreter/external.txi, doc/interpreter/func.txi, doc/interpreter/install.txi, doc/interpreter/interp.txi, doc/interpreter/intro.txi, doc/interpreter/java.txi, doc/interpreter/matrix.txi, doc/interpreter/munge-texi.pl, doc/interpreter/numbers.txi, doc/interpreter/package.txi, doc/interpreter/plot.txi, doc/interpreter/sparse.txi, doc/interpreter/stats.txi, doc/interpreter/strings.txi, doc/interpreter/system.txi, doc/interpreter/var.txi, doc/interpreter/vectorize.txi, libinterp/corefcn/error.cc, libinterp/corefcn/qz.cc, libinterp/corefcn/regexp.cc, scripts/general/accumarray.m, scripts/general/structfun.m, scripts/miscellaneous/edit.m, scripts/miscellaneous/setfield.m, scripts/miscellaneous/warning_ids.m, scripts/optimization/fminbnd.m, scripts/optimization/fzero.m, scripts/optimization/lsqnonneg.m: Use XREF as anchor prefix in documentation for clearer results in Info viewer. Correctly use @xref, @pxref, @ref macros in documentation. * scripts/plot/line.m: Remove extra ')' in @deftypefn. * libgui/src/qtinfo/parser.cc(find_ref): Change doc anchor search pattern to XREF.

--- a/doc/interpreter/external.txi
+++ b/doc/interpreter/external.txi
@@ -1201,7 +1201,7 @@
 
 The documentation of an oct-file is the fourth string parameter of the
 @w{@code{DEFUN_DLD}} macro.  This string can be formatted in the same manner
-as the help strings for user functions (@ref{Documentation Tips}),
+as the help strings for user functions (@pxref{Documentation Tips}),
 however there are some issue that are particular to the formatting of
 help strings within oct-files.
 
@@ -1231,7 +1231,7 @@
 character on the line.
 
 Octave also includes the ability to embed test and demonstration
-code for a function within the code itself (@ref{Test and Demo Functions}).
+code for a function within the code itself (@pxref{Test and Demo Functions}).
 This can be used from within oct-files (or in fact any file) with
 certain provisos.  First, the test and demo functions of Octave look
 for @code{%!} as the first two characters of a line to identify test