Clean up in javascripttypemaps.swg.

- following the same layout/order as pytypemaps
- added typemaps for `long long` and `unsigned long long`, which are
  only copies of those for `long` and `unsigned long` and hence are
  just experimental.

Lib/javascript/v8/javascriptfragments.swg

@@ -0,0 +1,23 @@
+/*
+
+  Create a file with this name, 'javascriptfragments.swg', in your working
+  directory and add all the %fragments you want to take precedence
+  over the default ones defined by swig.
+
+  For example, if you add:
+  
+  %fragment(SWIG_AsVal_frag(int),"header") {
+   SWIGINTERNINLINE int
+   SWIG_AsVal(int)(PyObject *obj, int *val)
+   { 
+     <your code here>;
+   }
+  }
+  
+  this will replace the code used to retrieve an integer value for all
+  the typemaps that need it, including:
+  
+    int, std::vector<int>, std::list<std::pair<int,int> >, etc.
+
+    
+*/