SolrCLI swallows errors from solr.cmd

It occurs on mad scenario in LUCENE-7534:

• solr.cmd weren't granted +x (it happens under cygwin, yes)
• coolhacker worked it around with cmd /C solr.cmd start -e ..
• but when SolrCLI runs solr instances with the same solr.cmd, it just silently fails

I think we can just pass ExecuteResultHandler which will dump exception to console.