Unit test improvements + Configuration settings bug fixes

+ All in-isolation tests--those tests that don't run against splunk--are complete
+ All configuration settings are consistent with Commands.conf.spec.xslx
+ Commands.conf.spec.xslx has been handed off to Matt for user documentation
Merge branch 'develop-1.2.0' of https://github.com/splunk/splunk-sdk-python into develop-1.2.0