general: add Grunt and Bower

* allows to install all the static files under invenio/base/static
* all the files are served without symbolic links
* npm install
* bower install
* grunt
* grunt clean # clean all the installed dependencies
* added instance/ in .gitignore
Merge pull request #143 from adrianp/poo

search: clearer collection name in search pages
Merge pull request #139 from giokokos/pu

general: add Grunt and Bower