Misc bug fix and code cleanup

1. Changed code not to send 'segmentation=none' to Splunk 4.x or earlier. Added tests to validate against Splunk 4.x.  (BTW, filed a JIRA issue against Java SDK for the same issue).
2. Changed a few Atom parsing methods from public to internal (made it equivalent to Java SDK).
3. Removed validation code to count events in the default index (in new tests checked in last week). This is due to a Splunk issue. Filed a JIRA issue to track future work for this. Please refer to https://jira.splunk.com/browse/DVPL-2257 for more details.
4. Removed some code redundency and duplication in index tests.
5. Renamed method name 'AlternateAdd' to 'Set'
Rename from code review feedback.