empty <table> left at end of column if first row would've been too tall

[adamwulf]

An empty node could be left at the end of a column if it was only filled with an whitespace text node. this fixes that and prevents that node from being left at the end of a column

http://jsfiddle.net/vqsd8x16/

fix:

http://jsfiddle.net/vqsd8x16/2/