Impossible to provide a BinaryTestFinder subclass in "finder", in jtt.

Currently an algorithm for com.sun.javatest.TestSuite.createTestFinder() is as follows:

1. if .jtd file exists, create new BinaryTestFinder, using
  new BinaryTestFinder().

2. if .jtd file doesn't exist, check for "finder" attribute in .jtt file.

==============
Having 1. is extrimely inconvenient. Suggestion is to change existing algorithm to:

1. if .jtd file exists,
   1.1. If "finder" attribute is provided in jtt, assume that this is a BinaryTestFinder
        subclass (and it does have a two-arg constructor):
        - load it using class name and create an instance using two arg constructor.

   1.2. If "finder" attr is missing in the jtt:
        create new BinaryTestFinder, using new BinaryTestFinder().

2. if .jtd file doesn't exist, check for "finder" attribute in .jtt file.