Adjust routes and add helper functions for bucket types.
Whitespace cleanup.
Add bucket types support to riak_kv_wm_buckets.
Add bucket type support to riak_kv_wm_props.
Add support for bucket types to riak_kv_wm_object.

* Changed explicit bucket type to use api_version = 3, unset/default
  uses 2.
* Left links alone but this could cause confusion later. PB already
  disallows bucket-types in links.
* Added another arity to riak_kv_wm_utils:format_uri to handle the
  inclusion of bucket types when generating the URI.
Go ahead and move maybe_bucket_type/2.
Add bucket types support to riak_kv_wm_keylist.
Add recognition of bucket types in riak_kv_wm_link_walker.

The original bucket-types proposal suggested that links and
link-walking would not be handled. This keeps consistency with that
proposal, returning 403 on link-walking requests scoped to a bucket
type other than the default.
Add support for bucket types to riak_kv_wm_index.
Fix typo.
Fix some more bugs in resources around bucket types.
Fix bucket name bug in wm_props.

Also use atom_to_binary/2 instead of l2b/a2l combo.
Add resource for bucket-type properties.
Add support for bucket types in JSON mapred.
Fix bad pattern in accept_doc_body.
Use ~s in the error response about unknown bucket types.
Coerce the datatype property into an atom.

When creating a bucket-type from the command-line, the `datatype`
property might not be an atom, so we should try to convert it to one
before passing it to the CRDT code.
Move the datatype property coercion into riak_kv_wm_utils:erlify_bucket_prop/1.
Merge pull request #698 from basho/bugfix/sdc-datatype-bucket-prop-format

Coerce the datatype property into an atom.
Update documentation comments and copyrights, cleanup whitespace.