Updated phpunit

Updated phpunit dependency due to a potential vulnerability.

Fixed a minimum requirement stability

0.9.2

fixed an issue in composer.json

A lot of minor fixes

0.9.1

a lot of fixes

Big refactoring

The client has been heavily refactored since I have excorporated the HTTP client from the package and created a new package called Surfer.

Refactored after having updated some packages

Code has been refactored due to the update of two used packages.

Fixed some bugs

Fixed some bug post refactoring.

Use ToolBag extension

Moved the helpers' code in a new package and refactored the source code to use that package.

setLimit() accepts 0

The ViewQueryOpts.setLimit() method now accept 0.

Added getDbPrefix() and fixed a bug

Fixed a bug that didn't return the ETag. Actually it wasn't a bug library, but a CouchDB's bug, but I have fixed the library to work anyway.
Added the method getDbPrefix().

In case of an HEAD method doesn't read the body

In general the content-Length entity-header field indicates the size of the entity-body, in decimal number of OCTETs, sent to the recipient, BUT in the case of the HEAD method, the size of the entity-body that would have been sent had the request been a GET. So I have added a check that avoid to read the response body. This fix affects only the SocketAdaptor, I'm still working on the cURL adaptor.