CppUnit - C++ port of JUnit Code

Add unit tests for CPPUNIT_ASSERT_DOUBLES_EQUAL() that test with
non-finite values.

Account for non-finite values in assertDoubleEquals().

Conditional inclusion of cmath rather than math.h removed since (1) it
was never used as HAVE_CMATH is never defined, and (2) cmath may move
isfinite() into namespace std.

Check for isfinite() and finite().

New autoconf macro to test for isfinite() in C++ mode.

Update email address of Steve M. Robbins

Arrange class initializers in correct order.

Ensure virtual class has virtual destructor.

Put a C++ statement in the first argument of CPPUNIT_ASSERT_THROW()
and CPPUNIT_ASSERT_NO_THROW().

Fix examples/hierarchy to actually return the result of the tests.
It is expected to fail, so mark it using XFAIL_TESTS in Makefile.am.

Do not fail dist-hook if $(distdir)/lib exists.