Changes

Bug 1219: IOUtil.testDirExe: Issue Process.destroy() in finalize block
to ensure launched native exe process terminates.
See Bug 1219 comment 58: It seems that on some Windows platforms the
launched native process using our test-exe keeps running even though we
issued Process.waitFor().
Hence we issue Process.destroy() in the finalize block to at least
attempt to terminate it.
Note: The Process implementation is platform specific and may vary.