Fixed two bugs and changed up export tests
* Corrected Awaiter.TryTake logic error
* Removed SearchExportArgs.Search property which is represented as a argument to Service.ExportSearch, not a member of SearchExportArgs
Bug fixes
* SearchResultStream and SearchPreview once again correctly track result metadata
* SearchResult now also tracks result metadata
Improved tests
* TestService.Transmitter1
* TestIndex
All new recordings
Added untracked recordings
Merge branch 'dnoble/refactor' of https://github.com/splunk/splunk-sdk-csharp-pcl into develop