fix - prevent execute method from overriding configureDefaultReporter

- remove provideFallbackReporter since it is no longer used
- prevent execute method from overriding configureDefaultReporter

closes jasmine#95

lib/jasmine.js

@@ -58,10 +58,6 @@ Jasmine.prototype.addReporter = function(reporter) {
   this.reportersCount++;
 };
 
-Jasmine.prototype.provideFallbackReporter = function(reporter) {
-  this.env.provideFallbackReporter(reporter);
-};
-
 Jasmine.prototype.configureDefaultReporter = function(options) {
   options.timer = options.timer || new this.jasmine.Timer();
   options.print = options.print || function() {
@@ -157,7 +153,9 @@ Jasmine.prototype.exitCodeCompletion = function(passed) {
 
 Jasmine.prototype.execute = function(files, filterString) {
   this.loadHelpers();
-  this.configureDefaultReporter({ showColors: this.showingColors });
+  if(this.reportersCount === 0) {
+    this.configureDefaultReporter({ showColors: this.showingColors });
+  }
 
   if(filterString) {
     var specFilter = new ConsoleSpecFilter({