Address some minor review comments on ep-engine xdcr changes

Here's the transcript of a mail from Chiyoung regarding this:

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Srini,

I reviewed and merged all your changes, and have some minor comments that need to be addressed:

1) http://review.couchbase.org/#change,14920 --> Please take a look at my comments and address them when you have time.

2) In the bg fetch callback, I think we should check if the item is resident or not for a temp item as well. For this, we should set the temp item's resident to false when it is created. Using CAS works for regular-type items only. As you probably know, couchbase also supports small-type items that don't have CAS in their meta data. Let's discuss this more tomorrow.

3) http://review.couchbase.org/#change,15439 -> Please address minor alignment issues.

Good test cases and bug fixes

Thanks,
Chiyoung

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