DirectSolrSpellChecker fails in distributed environment

While working on SOLR-2585, it was brought to my attention that DirectSolrSpellChecker has no test coverage involving a distributed environment. Here I am adding a random element to DistributedSpellCheckComponentTest to alternate between the "IndexBased" and "Direct" spell checkers. Doing so revealed bugs in using DirectSolrSpellChecker in a distributed environment. The fixes here roughly mirror those made to the "IndexBased" spell checker with SOLR-2083.