Factor levels not word diffed

[brodieG]

In:

diffPrint(factor(1:100), factor(c(1:99, 101)))

The 101 in the levels is not shown as a different word.

Indirectly reported by Frank

[brodieG]

Turns out this happens because in that case there is a difference on the last line of "content", and the factor levels end up in that same hunk, and our selection mechanism for what gets a word diff after the wrap diff is too coarse.