remove spurious print line in sieve api
output deferred index with sql-comment block

- deferred indexes / foreign keys are output after the table
  data. There was a regression introduced in the sieve rewrite
  where no sql comment block was included.  This follows the
  dbsake 1.0.X split-mysqldump behavior indicating the alter
  table uses innodb fast alter table and was specifically
  generated by dbsake.
frmdump -r/--raw-types -> -t/--type-codes

- This clarifies the option somewhat as it's purpose is to
  display the internal MySQL type codes.  Additionally this
  frees up the -r flag to allow for recursive .frm discovery
  in the future.
remove developing document

- this was duplicating the information from CONTRIBUTING.rst
  and was already rather stale.
fix too-short underline for Appendix section
fix inconsistent section underline in HISTORY.rst
fix incorrect escaping of sieve example output in README.rst
fix underline consistency
move subcommands to a separate document

- This makes commands show up nicer in the readthedocs theme.