Test nodes are started with erlang:open_port/2, using the -detached
option to erl. -detached causes the port returned from open_port/2 to
be closed automatically. Some test cases failed occasionally with a
badarg when attempting to close the port with erlang:port_close/1. To
avoid this the call to port_close/1 is now removed.

* siri/cuddle-with-tests:
  [reltool] Clean up work dir after test
  [observer] Add debug printouts in ttb_SUITE

This is to save space in daily tests.
Result of failed test cases are still saved.

A missing application directory is now classified as a warning if the
application is explicitly excluded.

The timeout of 5 minutes sometimes expired for test case
use_selected_vsn on some platforms.

* Make sure test node is terminated between each test
* Wait for expected applications to be started before continuing test
* Use ping instead of nodedown messages to check that node is down (to
  avoid failure due to no flush of inbox)

reltool_server_SUITE:create_standalone and create_multiple_standalone
failed on test hosts running hipe and smp. The reason was that the
escript used in these tests explicitly disabled smp, which in turn
made the emulator spit out warnings like this:

"<HiPE (v 3.10)> Warning: not loading native code for module beam_lib:
it was compiled for an incompatible runtime system; please regenerate
native code for this runtime system"

This was returned from the escript and did not match the expected result.

To overcome this, the escript (reltool/examples/display_args) is
changed and does no longer disable smp.

In order to handle paths with space, spawn_executable is now used
instead of spawn when starting nodes with open_port/2 in
reltool_server_SUITE.