Use C++11 raw string literals to avoid escaping double quotes. * parser.cc, workspace-view.cc, __lin_interpn__.cc, cellfun.cc, colloc.cc, data.cc, dirfns.cc, eig.cc, file-io.cc, find.cc, gammainc.cc, gl2ps-print.cc, graphics.cc, graphics.in.h, help.cc, input.cc, load-path.cc, load-save.cc, oct-hist.cc, oct-stream.cc, pager.cc, pr-output.cc, spparms.cc, symtab.cc, toplev.cc, tril.cc, urlwrite.cc, utils.cc, variables.cc, chol.cc, qr.cc, symbfact.cc, ov-struct.cc, octave.cc, pt-id.h, version.cc, mkoctfile.in.cc: Replace regular strings containing "\"" patterns with R"(..."...)".

--- a/src/mkoctfile.in.cc	Thu Jul 27 21:39:19 2017 -0700
+++ b/src/mkoctfile.in.cc	Fri Jul 28 10:34:33 2017 -0700
@@ -120,7 +120,7 @@
 quote_path (const std::string& s)
 {
   if (s.find (' ') != std::string::npos && s[0] != '"')
-    return "\"" + s + "\"";
+    return '"' + s + '"';
   else
     return s;
 }