Some HttpClient tests - like test/jdk/java/net/httpclient/SmokeTest.java, depend on non-library test classes that where developed for testing the HttpServer, such as ../../../com/sun/net/httpserver/FileServerHandler.java which requires compiling using `@compile`.

Instead of depending on HttpServer directly, these tests should use the common servers provided by the `HttpServerAdapters` offered by the test/jdk/java/net/httpclient/lib library. An adapted version of the ../../../com/sun/net/httpserver/FileServerHandler.java could be provided by the HttpServerAdapters helper.

There are also 5 implementations of stand-alone echo handlers in the httpclient test base. We should try to coalesce them into one implementation in HttpServerAdapters.