[Taverna-hackers] Small commit.

[Stuart O. <so...@cs...>]

Committed drop down icon for load and save. Couldn't find a matching 
icon in the Crystal Clear set, so I added a little down arrow to the 
existing ones (as a new icons of course).
Also, Antoon reminded me I said I would look at fetching the 
documentation for an operation, so I added the change for this - which 
turned out to be simple.

Stuart