[Audacity-devel] Clicktrack input string verification

[Steve <ste...@gm...>]

The "Optional Click Track Duration" is not verified and generates error
messages that are no user friendly such as:
"Nyquist returned the value: 10"

This issue was raised on the forum
http://forum.audacityteam.org/viewtopic.php?f=16&t=12968&p=49980#p49912

Attached is an updated version that verifies this input and produces a
meaningful error message if invalid data is entered.

I also made a couple of minor grammatical alterations to the first help
screen.

Steve