org-e-latex: Add xelatex as a possible processor

* contrib/lisp/org-e-latex.el (org-e-latex-pdf-process): Add xelatex
  as a possible processor.

contrib/lisp/org-e-latex.el

@@ -777,6 +777,18 @@ file name as its single argument."
 		   "bibtex %b"
 		   "pdflatex -interaction nonstopmode -output-directory %o %f"
 		   "pdflatex -interaction nonstopmode -output-directory %o %f"))
+	  (const :tag "2 runs of xelatex"
+		 ("xelatex -interaction nonstopmode -output-directory %o %f"
+		  "xelatex -interaction nonstopmode -output-directory %o %f"))
+	  (const :tag "3 runs of xelatex"
+		 ("xelatex -interaction nonstopmode -output-directory %o %f"
+		  "xelatex -interaction nonstopmode -output-directory %o %f"
+		  "xelatex -interaction nonstopmode -output-directory %o %f"))
+	  (const :tag "xelatex,bibtex,xelatex,xelatex"
+		 ("xelatex -interaction nonstopmode -output-directory %o %f"
+		  "bibtex %b"
+		  "xelatex -interaction nonstopmode -output-directory %o %f"
+		  "xelatex -interaction nonstopmode -output-directory %o %f"))
 	  (const :tag "texi2dvi"
 		 ("texi2dvi -p -b -c -V %f"))
 	  (const :tag "rubber"