Revert ANTLR 3.x from 3.5 to 3.2

This should fix Cassandra (which compiled against 3.2 and depends on
the org.antlr.runtime.Tokens.EOF_TOKEN field removed in 3.3) but could
have broken Solr, which currently depends on ANTLR 3.5.  Can't tell
since the Solr have preexisting config problems and don't pass right
now.

If Solr can't use ANTLR 3.2, then we'll may have to use the shade
plugin to ship multiple copies of ANTLR in order to allow Cassandra
and Solr to coexist in the same VM.