Have get_quoted_relname(), get_quoted_nspname(), and reorg_drop() sanity check arguments to prevent NULL pointer dereferencing and backend crash.
Have get_quoted_relname(), get_quoted_nspname(), and reorg_drop() sanity check arguments to prevent NULL pointer dereferencing and backend crash.

Fix for Issue #20.

bwtakacy/pg_repack,reorg/pg_repack,mr-mustash/pg_repack,reorg/pg_repack