Highlight filter does not support numbers

[pehrlich]

when you pass in a number, such as from a JSON blob, to the higlight filter, it produces the error "replace is not a function".

Presumably, everything should be cast to a string before any highlight is attempted.

[user378230]

I guess this should be resolved by #1402 (#1400) dc7f0d2

[pehrlich]

🎉