acknowledge Mathias Doenitz, Alexander Myltsev copyright in our main LICENSE

[pjfanning]

http-core/src/main/scala/org/apache/pekko/http/impl/model/parser/StringBuilding.scala

has this source header

/*
 * Copyright (C) 2009-2017 Mathias Doenitz, Alexander Myltsev
 *
 * Licensed 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.
 */

[pjfanning]

@jrudolph any idea where this originates? Unfortunately, we need to track down the original file so that we can see if the project has a LICENSE or NOTICE that we need to copy too.

[jrudolph]

It's not used any more since we moved to upstream parboiled2, see #251.