Support for Azure Gov clouds

Support to use the library in Azure Gov clouds has been added as a new parameter in the constructor:

var collector = new  HTTPDataCollectorAPI.Collector("{Your_Workspace_Id}", "{Your_Workspace_Key}", "ods.opinsights.azure.us");

Authorization header fix

Fixes authorization header calculation when checking the length of the content

Date field support and perf improvements

Adding support for "time-generated-field" thanks to @sergsalo and reduced hashing calls.

Patch 1.0.1

Adding optional parameters to ICollector

Initial release

v1.0.0

Update README.md