Changes: PerformanceCounter document changed to public + bug fiexes

Core Nuget: https://www.nuget.org/packages/Microsoft.ApplicationInsights/1.2.0

Channel Nuget: https://www.nuget.org/packages/Microsoft.ApplicationInsights.PersistenceChannel/1.2.0

BuildDefinition Output: https://mseng.visualstudio.com/DefaultCollection/AppInsights/_build#favDefinitionId=1822&_a=summary&buildId=2566253

Build Artifacts: file://vscsstor/CIDrops/AIC/AI-CoreSDK-GitHub-Master/20150805.1