[twgit] Init hotfix 'hotfix-0.1.2'.
Replacing a non existing method
Support for clearstatcache and stream context options

Add support for clearstatcache function and fixes up the issue related
to the empty list of context options passed to the stream wrapper when
registering it from DAV client class.
Deal with HTTP errors in the streaming download method

The implementation of streaming download proposed by Guzzle's
EntityBody class does not care about HTTP errors. When a resource is
not found on the server, we'd prefer considering an issue instead of
getting the HTML content of a 404 error page.
Merge branch 'hotfix-0.1.2'