release notes for OpenSRF 2.4.0-alpha

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
update ChangeLog for OpenSRF 2.4.0-alpha

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
bump up version number for OpenSRF 2.4.0-alpha

Signed-off-by: Galen Charlton <gmc@esilibrary.com>