Uploading article accessories

If you have additional files that make up an article -- such as images -- you can upload them using the steps described here.

Apologies as the process is a little fiddly. There is no web interface for this yet, it is all done with the LDS API -- which means you need to start a REBOL console session.

The basic stages are:

contribute article: you need to do this before you can know what article-id we assign it. Without that, you cannot set the links correctly. You can at this stage save rather than publish the article so it is not visible to other Library visitors
find article id: get this from the URL returned when you contribute your article. Look for something like ?article=ticle=dgt5w
library token: a token is the API equivalent of a cookie. It proves you are you when running the LDS interface. Get it from here: Library tokens. It will be emailed to your email address. Save it in the same folder from which you will run LDS-local.
run LDS: LDS is the API by which your console talks to the Library. Start a console session and execute this one line:
```
  do http://www.rebol.org/library/public/lds-local.r 
```
You can now test if your token works:
```
 probe lds/send-server/use-token 'token-test [] 
```
The status field should come back as:
```
   status: [0 0 "]  
```
If so, you are ready to upload some extra files for your article.
upload your files using the LDS command upload-article-accessory, eg:
```
   my-text-file: read %my-text-file.txt
   probe lds/send-server/use-token
            'upload-article-accessory
             reduce ["dgt5w" "my-text-file-name.txt" my-text-file]

   my-image: read/binary %my-image.png
   probe lds/send-server/use-token
            'upload-article-accessory
             reduce ["dgt5w" "my-image-name.png" my-image]
 
```
The lds/send-server block has three arguments:
- article-id
- file-name: what you want to call the file on the server
- file contents: either a string or a binary field
The files will be saved to a folder especially created for your article's accessories, eg (for article dgt5w)
```
href="http://www.rebol.org/library/arts/accessories/dgt5w/" 
```
Some commonsense validation/coercion is made to the filenames to ensure full cross-platform compatibility:
- lowercase only
- letters (a-z), digits (0-9), hyphens and periods (-.) only
- first character must be a letter.
The object that comes back in reply lists all files in the articles folder, so you can check everything is there.
update the article: The links in the article now need to point to the article files, eg:
```
"href=http://www.rebol.org/library/arts/accessories/dgt5w/my-image-name.png" 
```

And you are done!