#183 CPPUNIT_ASSERT_DOUBLES_EQUAL works incorrectly

[testpu]

CPPUNIT_ASSERT_DOUBLES_EQUAL macros is not failed when actual value is equal to NAN.
For example:
CPPUNIT_ASSERT_DOUBLES_EQUAL(1.0, std::numeric_limits<double>::quiet_NaN(), 1e-12);

This test is not failed.