Move to grunt for building all distribution files.

* canonical version number of jasmine-core is now is package.json
* `grunt buildDistribution` builds jasmine.js, jasmine-html.js, jasmine.css and outputs them to the dist dir
* `grunt buildStandaloneDist` builds the example spec runner files and compresses them to dist/jasmine-VERSION.zip
* `grunt compass` compiles jasmine.css
* jasmine.Env handling of version is backwards compatible, but uses the version string directly (and nicely deprecated)
* Ruby/thor tasks that did the above deleted

grunt/config/compass.js

@@ -0,0 +1,10 @@
+module.exports = {
+  jasmine: {
+    options: {
+      cssDir: 'src/html',
+        sassDir: 'src/html',
+        outputStyle: 'compact',
+        lineComments: false
+    }
+  }
+};