prepare 1.0.0-beta24 release

[eli-darkly]

[1.0.0-beta24] - 2019-09-13

Added:

• LdValue now has methods for converting to or from a list or dictionary, rather than using the Newtonsoft.Json types JArray and JObject.
• HTML documentation for all public types, methods, and properties is now available online.

Changed:

• The new name of ImmutableJsonValue is LdValue.
• The SDK no longer has a dependency on Xam.Plugin.DeviceInfo.
• When accessing a floating-point flag value with IntVariation, or converting a floating-point LdValue to an int, it will now truncate (round toward zero) rather than rounding to the nearest integer. This is consistent with normal C# behavior and with most other LaunchDarkly SDKs.

Removed:

• All public methods and properties now use LdValue instead of JToken.

Fixed:

• Fixed a bug that caused a string flag value that is in an ISO date/time format, like "1970-01-01T00:00:01.001Z", to be treated as an incompatible type by StringVariation (because Newtonsoft.Json would parse it as a DateTime by default).
• On Android, an HTTP connection timeout could leave a connection attempt still happening in the background-- even though the timeout would still happen normally as far as the SDK was concerned-- until the default timeout for the Android HTTP handler elapsed, which is 24 hours. Now it will properly stop the connection attempt after a timeout.
• Fixed an implementation problem that caused excessive overhead for flag evaluations due to unnecessary JSON parsing.