Marked some tests skipped if directories mismatch.

Strangly on my machine the function tempnam returns something
different than expected.

tempnam('/foo', 'bar');

returns a file located in /private/foo. The way this test works
does not allow this behaviour. This is why we test this condition
and mark the test skipped.
Normalize stream wrapper path.

This way it is not important to remember appending a / to the end of
the stream_wrapper string.
Extended documentation about chunked uploads and Gaufrette.
Merge pull request #3 from sheeep/release-1.0

Documentation / Test / Little Improvement