feat: add CLI support for different hash func and type

[daviddias]

@kumavis I've imported the changes you made on the DAG API PR -- #636 -- to here, but getting this error:

  1) cli --all block with daemon off (requiring js-ipfs core directly) put with flags, format and mhtype:

      AssertionError: expected 'cZxfGwVjp1wDnUowKQ5sR6zEQubxB8Dys2dMZ4t8a3dnse' to deeply equal 'z43AaGF23fmvRnDP56Ub9WcJCfzSfqtmzNCCvmz5eudT8dtdCDS'
      + expected - actual

      -cZxfGwVjp1wDnUowKQ5sR6zEQubxB8Dys2dMZ4t8a3dnse
      +z43AaGF23fmvRnDP56Ub9WcJCfzSfqtmzNCCvmz5eudT8dtdCDS

      at ipfs.then (test/cli/test-block.js:21:24)
      at process._tickDomainCallback (internal/process/next_tick.js:129:7)

Was this working for you before?

[kumavis]

yeah was working before -- not sure whats wrong here

[kumavis]

@diasdavid the hash matches the eth-block test z43AaGF23fmvRnDP56Ub9WcJCfzSfqtmzNCCvmz5eudT8dtdCDS

but the test message/label doesnt match?

[daviddias]

just fixed it, the if clause was wrong because when I migrated, I kept the option to do CIDv0 too and introduced a bug, now it is good :)