Fixes docs, adds some code restructure

I have to say that I am working with queues for a long time now. I have some PHP implementations as well, but it seems that bernard is going to become what I wanted to start on my own. So let this be my introduction to this project (with the pheanstalk driver).

I have to do some proof of concept code for myself to be sure that this is really what I need, but I think that I am going to be commited to this project.

Thanks guys for creating this awesome library.
In some cases it is better to have them: for example in case where the property name does not expose the type, like $prefetch, where it is an integer. It is obvious if someone looks at the constructor. Should I remove documentation in these cases as well?