better java6 compat fix

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
updated unit tests to match new auth behaviour

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
okhttp 1.5.4 (because I can)

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
fixed minor issue with wagon http header management

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>