Allow shortlinks to pluralized crop names

[Skud]

When I'm posting on Growstuff about my tomatoes, I have to say tomato (i.e. use the singular) for the link to work. I'd like to be able to use the plural when appropriate.

For this to work we'd probably have to include plurals in the database, and then look there as well as the main name when creating links.

It also occurs to me that one might want to use alternate names, eg. "rocket" instead of "arugula" when linking, which is a similar issue.

This obviously needs a lot of thought and so on, but I just wanted to flag it as a "would be nice..."