Don't repeat type name in update mapping

[clintongormley]

Currently the update_mapping API requires the type name to be repeated in the body, eg:

POST /my_index/my_type/_mapping
{
    "my_type": {
        "properties": {...}
    }
}

This repetition is confusing and unnecessary. Instead should be OK to do:

 POST /my_index/my_type/_mapping
{
    "properties": {...}
}

Bonus points for making the change in a backwards compatible way :)

[kimchy]

first, I don't fully agree with this issue, I don't think putting the type as top level is repetitive. It actually maps into what we are going to return in the get mapping API.

second, if we are going to do it, we have to make it backward compatible.

[dakrone]

@kimchy this change is entirely backwards compatible. Either specifying the type (old method), or not specifying the type are supported.

See http://p.writequit.org/org/4483-dont-repeat-type.html for examples.

[dakrone]

@kimchy I see your comment about the additional parameters at the top level, I'll make sure this is entirely backwards compatible with those settings, thanks for pointing those out!