rounding errors cause empty white space

[Kajakske]

If the total available size is not dividable between the desired amount of columns, you possibly get empty space.
Example:
Available width: 20px
Desired cols: 3.

Each col width: 6.66px, current code rounds it to 7px.
7px x 3 cols cuases the last block to jump to a new line.
Flooring the width results in 3 x 6px cols.

Ideally, it should create blocks 6, 6 & 7px wide, however, my fix is easy and results in only 2 empty pixels on the right and 3 cols as desired.

[laurensV]

This problem still exists (off by one pixel due to rounding issues).