Add better logging for stacks integration

[jkeck]

Part of sul-dlss/media#155

We currently have logging in places when we reject sessions due to invalid configurations (and other reasons), but since we're seeing sessions getting rejected that should be accepted (and then are accepted later w/o intervention) it would be helpful to be able to determine why the sessions are being rejected in these cases.

rejectSession() already outputs a generic line in the log (along the lines of HTTPStreamerAdapterCupertinoStreamer.onPlaylist[stacks/_definst_....]: Session not accepted) so we should be able to add some addl. context that we can use to determine what's going on (w/o blowing the logs up).

dlss-wowza/src/edu/stanford/dlss/wowza/SulWowza.java

Lines 279 to 290 in 3ad1703

	if (validateStacksToken(stacksToken) && validateUserIp(userIp) && validateStreamName(streamName))
	{
	String druid = getDruid(streamName);
	String filename = getFilename(streamName);
	if (druid != null && filename != null && verifyStacksToken(stacksToken, druid, filename, userIp))
	httpSession.acceptSession();
	else
	httpSession.rejectSession();
	}
	else
	httpSession.rejectSession();

If we can add the reason that the if/else statements fall through to the session being rejected that could give us some insight into the issues we're seeing.

There are also additional unlogged cases (e.g. if the HTTP request to Stacks is unsuccessful) that might also be at play (and may be worth throwing some sort of logging/HB reporting).

dlss-wowza/src/edu/stanford/dlss/wowza/SulWowza.java

Lines 478 to 481 in 3ad1703

	if (status == HttpURLConnection.HTTP_OK)
	return true;
	else
	return false;