Update version to 104.4

This includes a feature that allows specifying whether or not to use default authentication.
Merge pull request #456 from restsharp/Haacked-patch-2

Update version to 104.4
Default user agent should be name/version
Merge pull request #460 from restsharp/haacked/fix-default-user-agent

Default user agent should be name/version
Sending a DELETE reqeust asynchronously with a request body from the client didn't actually include the body. This is now fixed so that the body is now in fact included in the request
Merge pull request #461 from chribben/delete-request-with-body

Sending a DELETE reqeust asynchronously with a request body from the cli...
Added tests for deserializing different enum types

This demonstrates a bug where int is always assumed as enum type.
Support for enums of any available enum type
Merge pull request #467 from arangas/enum-type-parsing

Deserialization for enums of any type
Merge branch 'master' of https://github.com/restsharp/RestSharp

Conflicts:
	RestSharp/RestClient.cs