Update .gitignore file

I updated the .gitignore file using the Visual Studio template from
the GitHub .gitignore repository.
Change license to Apache License 2.0

I modified the LICENSE.md document. I removed the MIT license text and
replaced with with the text for Apache License 2.0.
Imported Log4netProvider source code.

I imported the source code for the log4net provider for Neuron ESB
from the main Neuron ESB repository.

I attached the Apache 2.0 license to the source code.

I updated the references in the Log4netProvider project to use the
Neuron ESB SDK NuGet package.
Updated README.md

I updated README.md with instructions on how to build the project and
how to configure the logging provider for the application.
Merge branch 'release/3.5.0'