A few weeks ago an interesting email popped into the fashion-mommy inbox. It  came from online comparison site Idealo and it asked the question would I be interested in taking part in the Idealo Spring Dress Challenge?  As I live in dresses, rarely wearing anything else, I wanted to find out more. The premise was simple, selected bloggers were asked to search the net for a dress under £100 that they really liked, and then test drive the dress in order to produce a review, producing  a comprehensive list of the best Spring dresses around. Idealo would supply the dress of your choice – the blogger had the really difficult…