Fix typo on stashing sql in SqlQuery
Handle warnings on queries with no subqueries

Warnings on queries with no subqueries would blow up on the SqlQuery#table method.  The subqueries array is populated from the EXPLAIN output, so is empty for inserts/updates/deletes.

The report view now shows "Table unknown" for such queries, not sure what the best way of picking out the table name is for those cases.
Fix "undefined method `reverse' for nil:NilClass"

AFAICT, it isn't safe to call arel.to_sql for insert statements.  Once ActiveRecord has set up its BindSubstitution visitor, the bind values must always be present, so you must go via DatabaseStatements#to_sql(arel,binds)
Merge pull request #30 from jdelStrother/insert-fixes

Fix errors on INSERTs