Adding bundler plugin to generate OSGI manifest

While I was taking training for cassandra, I noticed that the driver driver did not contain the OSGI-manifest hence I added.  BTW, We (the company, where I work for) are using the hector and we will moving to CQL soon and our project is based on OSGI since I made change in the public repo so it will be useful for others.  The same needs to apply to version 1.x too.