If you need to use PUT then as far as I'm aware you're still going to need a plugin for FM13. Although the Insert From URL script step now supports more verbs than previously (e.g. FTP, POST, etc) PUT isn't one of them, see: http://www.filemaker.com/13help/en/html/scripts_ref1.36.50.html
Personally I like the BaseElements plugin from Goya, which supports PUT and should help you with this. See: http://www.goya.com.au/baseelements/plugin and specifically: https://github.com/nickorr/BaseElements-Plugin/wiki/Functions#be_http_put_data
Hope this helps
AFAIK, there is no native way to do REST commands in FMP.
I have a very robust REST API call system that uses the cURL command through the PHP plugin SMARTPILL.
I structured the API calls as records in a commands table. The URL would be a combination of fields from the command record. The command table also has a field for the send type. For example: PUT, GET, DELETE. Because not all REST commands use PUT.
The XML data was coded in a field as well formed XML with tokens to be substituted with real data at run time.
For example I would put this in the XML Data field and use a substitute command to fill in live data
XML Data field:
command::XML Data ;
The cURL command would be fed this XML as the data string to go along with the URL that was built from the command record. As you encounter problems with the REST service and/or your data you’ll have to modify the REST script to allow for them. Various error trapping issues and, of course, logging every command and its reply. The log is essential for troubleshooting production problems.