Added options to MathJax plugin, also updated documentation

docs/plugin-use.md

@@ -22,6 +22,14 @@
 
 **Example**: ```(mathjax)```
 
+### Options
+
+`:force`, when specified with a true value, will force the inclusion of MathJax, even if no posts are tagged "math".  Default value is `nil`.
+
+`:mathjax-url` specifies the location of the `MathJax.js`.  The default value is `"http://cdn.mathjax.org/mathjax/latest/MathJax.js"`.  This is useful if you want to force a specific value of MathJax, or if you have a local copy of MathJax and want to use that version.
+
+`:config` allows the specification of the config parameter of `MathJax.js`.  The default value is `"TeX-AMS-MML_HTMLorMML"`.  
+
 ## ReStructuredText
 
 **Description**: Some people really like [ReStructuredText](http://docutils.sourceforge.net/rst.html). Who knows why? But it only took one method to add, so yeah! Just create a post with ```format: rst``` and the plugin will do the rest.

plugins/mathjax.lisp

@@ -9,22 +9,40 @@
 
 (in-package :coleslaw-mathjax)
 
-(defvar *mathjax-header* "<script type=\"text/x-mathjax-config\">
+(defvar *mathjax-config-header* "<script type=\"text/x-mathjax-config\">
   MathJax.Hub.Config({
     tex2jax: {
       inlineMath: [['$$','$$']]
     }
   });
 </script>
-<script type=\"text/javascript\"
+")
-src=\"http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML\">
-</script>")
 
-(defun enable ()
+(defvar *mathjax-load-header-no-config* "<script type=\"text/javascript\"
+src=\"~A\"> 
+</script>
+")
+
+(defvar *mathjax-load-header-with-config* "<script type=\"text/javascript\"
+src=\"~A?config=~A\"> 
+</script>
+")
+
+(defun enable (&key force 
+		 (mathjax-url "http://cdn.mathjax.org/mathjax/latest/MathJax.js")
+		 (config "TeX-AMS-MML_HTMLorMML"))
   (labels ((math-post-p (obj)
              (member "math" (content-tags obj) :test #'string=))
            (mathjax-p (obj)
+	     (or force
 		 (etypecase obj
 		   (content (math-post-p obj))
-               (index (some #'math-post-p (index-posts obj))))))
+		   (index (some #'math-post-p (index-posts obj)))))))
-    (add-injection (list *mathjax-header* #'mathjax-p) :head)))
+
+    (let ((mathjax-header 
+	   (concatenate 'string
+			*mathjax-config-header*
+			(if config
+			    (format nil *mathjax-load-header-with-config* mathjax-url config)
+			    (format nil *mathjax-load-header-no-config* mathjax-url)))))
+      (add-injection (list mathjax-header #'mathjax-p) :head))))