End to end testing with Cactus

LedgeWebappTestCase base class should be created that would do the following:

1. Retrieve a refernce to the real LedgeServlet instance and store it in an instance variable inside the server side setUp() method.
2. Provide a proceed() method that would forward the request to the real LedgeServlet instance, using provided HttpServletRequest/HttpServletResponse objects.

Individual test case class would describe a complete testing scenario comprised of multiple requests. Each test method would describe a single request within the scenario. The following methods need to be implemented for each request N:

Notice that all testRequestN() methods are identical. It seems that it's possible to eliminate them completly by overriding some of the JUnit / Cactus functionality - more research is needed.

Prequisites tests within the testcase are executed in alphabetical order (remember to use leading zeros as necessary to enforce proper ordering) testcase instances are reused across multiple tests - otherwise static variables + additional precautions for maintaing proper state need to be used