[Gvsig_english] New field calculator::some remarks

[Wolfgang Qual]

Hi developers,
the description of the operator "+" for string-values is wrong, as the 
description says that it would return a numeric value. Well, this is not a 
big problem, as the calculator itself is really helpful. Congrats!

Second: it would be good, if arguments for the calculation would "jump" into 
the right place, when the cursor is at the correct position. Example:
I click on "max" and max() appears in the expression window. However, when I 
place the cursor in between the brackets, and click on the desired column, 
the column name will be written behind max(). 

Third: What type does the expression file need to be? Textfile? Would be cool, 
if I could save an expression for later usage by clicking on a button "Save 
expression". I can also copy an expression and open a text-editor, but this 
would speed things up a little bit.

Best,
Wolfgang