rosmatlab: improved MexMethodMap implementation by using a templated
functor
rosmatlab: rosmatlab::Options: added support for cells for multi-valued
options
rosmatlab: fixed copy construction of message struct arrays with more
than 1 element
rosmatlab: simplified ros.Subscriber.poll class definition code using
varargout
rosmatlab_rosbag: added method data to rosbag.Bag and rosbag.View to
retrieve the whole bag/view at once

* moved implementation of class Query to a seperate header/cpp file
* added method rosbag.View.start to set the iterator to the start
position