toMatch requires the expected to be a String or RegExp

- Otherwise it was using the `toString` as the RegExp, which is almost
  definitely _not_ what you want.

Fixes #723

src/core/matchers/toMatch.js

@@ -1,8 +1,12 @@
-getJasmineRequireObj().toMatch = function() {
+getJasmineRequireObj().toMatch = function(j$) {
 
   function toMatch() {
     return {
       compare: function(actual, expected) {
+        if (!j$.isString_(expected) && !j$.isA_('RegExp', expected)) {
+          throw new Error('Expected is not a String or a RegExp');
+        }
+
         var regexp = new RegExp(expected);
 
         return {