NetUtil update to provide custom request headers with downloadURL and getURLInputStream

The current calls do not allow for direct manipulation of request headers or client code access to response headers. Caitlyn's modifications used in Timezone project are being used as a model for this change with some modifications to be more generic, two new methods will be added tentatively meeting these prototypes:

public static InputStream getURLInputStream(String aURL, String aUsername, String aPassword, HashMap<String, String> someConnectionProperties)

{..};

public static boolean downloadURL(String aURL, String aFilename, String aUsername, String aPassword, boolean isHttpGetUrl, HashMap<String, String> someConnectionProperties){..}

;

The client code will pass in all required request properties as entries in someConnectionProperties, the methods will use these to build the request header and remove these entries from the map. The response header will then be parsed into this map so that the client code can access the information in the response header.

This change will not affect any current builds as the old methods will be unchanged, but this functionality will be required for both v201101 google update and timezone projects.