… encoding

Although HtmlWeb class allows to ignore resp.ContentEncoding by OverrideEncoding property, it cannot help in the case where resp.ContentEncoding has encoding name which is not supported by Encoding class. This is because Encoding.GetEncoding method throws ArgumentException in that case.

When OverrideEncoding is provided, the result from resp.ContentEncoding has not been used, so that simply skipping Encoding.GetEncoding method call can make it work.

EncodingNotSupportedException is added in order to notify that such not supported content encoding is received in the response, with the information of the received content encoding name. This is more helpful than ArgumentException.

…ible in public

modify access modifier of Encoding property of EncodingNotSupportedException from internal to public.

wrap HttpRequest and HttpResponse with interfaces, and make HtmlWeb class testable.

add a test project targeting multiple .NET version.
copy the existing tests in HtmlAgilityPack.Tests.Net45.

add test code generator

add test code for HtmlWeb.Load method

It turned out NUnit tests are not running with core 2.0. Therefore, changed test project target to core 2.1 so that we can run tests over .NET Core.

add mshome.html file load to mock in HtmlWebTests.TestLoad.
modify how to get assembly location in generated test code in HtmlWebTestGenerator.

The code was never be active because of the wrong condition and wrong symbols in the processor directive.

correct it so that the code is activated in net4.5 and newer.
add a preprocessor symbol in two projects so as to build HtmlAgilityPack.Master solution also with Debug configuration.