[task] changed AuthService#retrieveAccessToken() to use Jersey
[task] changed AuthService#retrieveAccessToken(String) to use Jersey
[task] changed refreshAccessToken(AccessToken, Scope[]) to use Jersey
[refactor] remove parameter on encodeClientCredentials(String, String)
[task] changed getRedirectLoginUri() to use Jersey
[cleanup] changed to a plain old string for charset name
[cleanup] removed explicit commons codec dependency
[cleanup] making final what has to be final
[cleanup] minor refactorings, cleanup
[task] changed getResource() to use Jersey
[cleanup] switched to guava preconditions
[task] changed deleteResource() to use Jersey
[fix] added handling of mapping and network errors from jersey
[cleanup] minor refactorings, cleanup
[task] changed createResource() to use Jersey
[task] changed update-/replaceResource() to use Jersey
[fix] added apache http client

jersey fails to send PATCH requests with Java HttpUrlConnection, so
apache http client is introduced.