Whitespace remover

Two different jobs: collapsing runs of spaces to one and trimming each line, or removing every space, tab and line break so the text becomes a single unbroken string.

Collapsing is what you want for prose — double spaces after full stops, trailing spaces at line ends, stray tabs from a paste. Removing everything is for data: a card number, a hash or a key that has picked up spaces from being wrapped across lines. Both matter more than they look, because trailing whitespace is invisible and is a common cause of a comparison failing when two values appear identical. Non-breaking spaces are worth a special mention: they are not matched by a plain space search, so a find-and-replace on " " leaves them behind. Both options here treat them as whitespace.