.csv column reassignment UI about disco

[lippoldt]

@martinjaggi @PaulMansat I propose to slightly change the style to either 3 line arrangement or one line, which one do you prefer?


Adding another line will integrate more smoothly into the structure, for a one liner I would also change some of the parent div's (i.e. simplify overall structure)

[martinjaggi]

whichever you prefer.
arrow should point from source text field to target td

[mmilenkoski]

closing this because it was resolved in #93