Documentation update + a couple of missing property additions + fix to Splunk 6.1 test failures

Missing properties were found while documenting implemented properties.
These new properties are available. They have non null values in Splunk
6.1 only:

* Index.ColdPathMaxDataSizeMB
* Index.HomePathMaxDataSizeMB
* SavedSearch.Action.Email.SubjectAlert
* SavedSearch.Action.Email.SubjectReport