fixes #236 initial commit for grunt file

This is semi-hardcoded for the various extensions. 
Please review package.json to see if there is anything else to add

Instructions
-------------------------
* Download and install nodejs and grunt
* Install npm packages by typing:

          npm install 

* To generate the distribution files

          grunt

To Do
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- [ ] calling of phantomjs with jasmine
- [ ] integration of jsduck documentation 

Features
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- [x] Generate js, css, min js and min css files under lib folder