click: input threads must not have comments in them

[ashelkovnykov]

From @hosted-fornet, here:

See the parsing of inline thread files that happens on line 191.

A reasonable solution would be to document the differences in parsing the inline thread from the standard Hoon parser (e.g. "comments will break it" and whatever else).

A better solution would be to modify the parsing to properly handle comments.

Another improvement might be the inclusion of an example of an inline thread file that will work.