Exclude a column from a table dump #596

Hi,

As i dump tables with a lot of columns in it, there are some times where i want to exclude only one or two columns containing a lot of data that i dont want and that are only slowering my extraction process.
It is a bit annoying to enumerate all the columns i want as it can go sometimes to more than 50 columns. A faster way would be to just tell sqlmap to exclude one or two columns from the whole table dumping.