Minor refactoring of testframe.c testing framework (#4930)

Added setup and cleanup callback parameters to TestInit() to perform
setup and cleanup tasks once for whole test program

Removed TestCleanup() function since its functionality is covered by
PerformTests()

Added check of the HDF5_NOCLEANUP environment variable in
GetTestCleanup()

c++/test/testhdf5.cpp

@@ -32,8 +32,6 @@
         PerformTests() -- Perform requested testing
         GetTestSummary() -- Retrieve Summary request value
         TestSummary() -- Display test summary
-        GetTestCleanup() -- Retrieve Cleanup request value
-        TestCleanup() -- Clean up files from testing
         GetTestNumErrs() -- Retrieve the number of testing errors
 
  ***************************************************************************/
@@ -57,7 +55,7 @@ main(int argc, char *argv[])
         // caused deliberately and expected.
         Exception::dontPrint();
         /* Initialize testing framework */
-        TestInit(argv[0], NULL, NULL, 0);
+        TestInit(argv[0], NULL, NULL, NULL, NULL, 0);
 
         // testing file creation and opening in tfile.cpp
         AddTest("tfile", test_file, NULL, cleanup_file, NULL, 0, "File I/O Operations");
@@ -112,10 +110,6 @@ main(int argc, char *argv[])
     if (GetTestSummary())
         TestSummary(stdout);
 
-    /* Clean up test files, if allowed */
-    if (GetTestCleanup() && !getenv(HDF5_NOCLEANUP))
-        TestCleanup();
-
     /* Release test infrastructure */
     TestShutdown();