Fix inconsistent use of `$this->writer` vs local variable
Makes Guzzle compatible with TYPO3 Flow Framework out of the box

This small change allow using the guzzle/Guzzle out of the box with TYPO3 Flow.

Unfortunately TYPO3 Flow can not load second entry given in the manifest for autoloading (Source: http://docs.typo3.org/flow/TYPO3FlowDocumentation/stable/TheDefinitiveGuide/PartIII/PackageManagement.html#using-3rd-party-packages )

Only one trick is needed in Flow's Settings.yaml to allow using Guzzle:

:1. excluding annotations
 excluding this package from Object Framework (Note: this makes AOP for Guzzle off)
<pre>
TYPO3:
  Flow:
    object:
      excludeClasses:
        'guzzle.Guzzle': ['Guzzle\\.*']
</pre>
).
Makes Guzzle compatible with TYPO3 Flow Framework out of the box

This small change allows using the guzzle/Guzzle out of the box with TYPO3 Flow.

Unfortunately TYPO3 Flow can not load second entry given in the manifest for autoloading (Source: http://docs.typo3.org/flow/TYPO3FlowDocumentation/stable/TheDefinitiveGuide/PartIII/PackageManagement.html#using-3rd-party-packages )

Only one trick is needed in Flow's Settings.yaml to allow using Guzzle:

:1. excluding annotations
 excluding this package from Object Framework (Note: this makes AOP for Guzzle off)
<pre>
TYPO3:
  Flow:
    object:
      excludeClasses:
        'guzzle.Guzzle': ['Guzzle\\.*']
</pre>
).
Updated RedirectPlugin to redirect using GET as required by RFC.  Always use GET regardless of "strict redirects" setting.
Added tests to verify that 303 redirects use GET.
Setting CURLOPT_SSL_VERIFYHOST to 0 when certificateAuthority is false to match documentation

When $certificateAuthority is False,
the documentation for setSslVerification() in the Interface, at:
https://github.com/guzzle/guzzle/blob/master/src/Guzzle/Http/ClientInterface.php
says:
"Setting $certificateAuthority to FALSE will turn off peer verification, unset the bundled cacert.pem, and disable host verification."

The unit test was also fixed.