Rename RemoteProxySettingsConfiguration to GlobalRemoteProxySettings (to be inline with similar global settings)

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge pull request #43 from sonatype/simplify-remote-proxy-settings

REVIEW: Rename RemoteProxySettingsConfiguration to GlobalRemoteProxySettings (to be inline with similar global settings)