feat(ox-moderncv.el): Add support for some latex preamble variables

Adds support for the latex variables set in the preamble:
- pagenumber: true or false
- columnwidth for the date columns using `setlegnth`
- page geometry: use anything that goes into the parameters of the
geometry latex package

.gitignore

@@ -1,2 +1,7 @@
 *.elc
 /dev.org
+.dir-locals.el
+Makefile
+*~
+test/
+export-latex.el

ox-moderncv.el

@@ -56,6 +56,9 @@
   '((:latex-class "LATEX_CLASS" nil "moderncv" t)
     (:cvstyle "CVSTYLE" nil "classic" t)
     (:cvcolor "CVCOLOR" nil "blue" t)
+    (:cvgeometry "CVGEOMETRY" nil nil t)
+    (:cvcolumnwidth "CVCOLUMNWIDTH" nil nil t)
+    (:cvpagenumber "CVPAGENUMBER" nil nil t)
     (:mobile "MOBILE" nil nil parse)
     (:homepage "HOMEPAGE" nil nil parse)
     (:address "ADDRESS" nil nil newline)
@@ -94,6 +97,16 @@ holding export options."
      ;; cvcolor
      (let ((cvcolor (org-export-data (plist-get info :cvcolor) info)))
        (when (not (string-empty-p cvcolor)) (format "\\moderncvcolor{%s}\n" cvcolor)))
+     ;; cvgeometry
+     (let ((cvgeometry (org-export-data (plist-get info :cvgeometry) info)))
+       (when (not (string-empty-p cvgeometry)) (format "\\usepackage[%s]{geometry}\n" cvgeometry)))
+     ;; cvcolumnwidth: if you want to change the width of the column with the dates
+     (let ((cvcolumnwidth (org-export-data (plist-get info :cvcolumnwidth) info)))
+       (when (not (string-empty-p cvcolumnwidth)) (format "\\setlength{\\hintscolumnwidth}{%s}\n" cvcolumnwidth)))
+     ;; cvpagenumber: to suppress automatic page numbering for CVs longer than one page
+     (let ((cvpagenumber (org-export-data (plist-get info :cvpagenumber) info)))
+       (when (and cvpagenumber (equal cvpagenumber "false"))
+       (format "\\nopagenumbers{}\n")))
      ;; Possibly limit depth for headline numbering.
      (let ((sec-num (plist-get info :section-numbers)))
        (when (integerp sec-num)