Fix to run-away mem allocation by CC, diagnostics

- fixed a bug in doDescribeServices that would return arbitrary data
  (triggered when CLC asked about a node no longer in CC's cache, due to
  departure)
- added guards in input->urisLen[] marshaling to minimize memory
  balooning
- additional TRACE-level logging around ncDescribeResourceStub
- better diagnostics when a helper CC child process doesn't exit
- used a constant, MAX_SERVICE_URIS, instead of 8 everywhere

Fixes EUCA-6097
Merge remote-tracking branch 'origin/dev/dmitrii/cc-badness' into testing
Merge branch 'testing' of git.eucalyptus-systems.com:eucalyptus into testing