Apm-agent-dotnet: Add License Header

[lreuven]

We need to add headers for all source code files. If it isn't a source code file, no need.
/*

Licensed to Elasticsearch B.V. under one or more contributor
license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright
ownership. Elasticsearch B.V. licenses this file to you under
the Apache License, Version 2.0 (the "License"); you may
not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License. */

[gregkalapos]

@Mpdreamz do we want to have the same header in the .NET client and in APM Agent?

I see you agreed on a shorter one here.

I personally would prefer the shorter one, but other agents use this longer version.

For C# I think we should use // comment instead of /*... */ - that's more C#.

So... question: which one do we take?

// Licensed to Elasticsearch B.V under one or more agreements.
// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
// See the LICENSE file in the project root for more information

Or

(with some nicer formatting)

// Licensed to Elasticsearch B.V. under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Elasticsearch B.V. licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.

[Mpdreamz]

.NET projects can use the shorter one as exception since this follows .net best practices (see PR and discussion on the .net client) @gregkalapos it's the one I intend to use.

[gregkalapos]

.NET projects can use the shorter one as exception since this follows .net best practices (see PR and discussion on the .net client) @gregkalapos it's the one I intend to use.

Perfect! I'd also prefer that one. @lreuven are we good to go with that one?

[Mpdreamz]

I bit the bullet and added the headers to the clients master and 7.x branches using this script: https://github.com/elastic/elasticsearch-net/pull/4690

@gregkalapos happy to run the script on this repository too at a time of your chosing 😄 let me know.

838 should cover all new files being created on this repos too.

[gregkalapos]

I bit the bullet and added the headers to the clients master and 7.x branches using this script: elastic/elasticsearch-net#4690

@gregkalapos happy to run the script on this repository too at a time of your chosing 😄 let me know.

838 should cover all new files being created on this repos too.

Awesome! Feel free to run it any time, we can merge it now - these are changes that should not cause big merge conflicts (famous last words...), only the top of the files are changed.

[gregkalapos]

Done by @Mpdreamz 👏