suppression of error messages

[bob <bo...@accurev.com>]

btw--

WebMacro has a habit of being verbose in it's error messages,
which can get annoying.

If you attempt $variable.that.results.in.null, it'll spew forth

<!-- Unable to locate $variable.that.results.in.null -->

Which is useful sometimes, but gets in your way sometimes
also, when you do something like this:

	<input type="text" value="$possiblyNull"/>

iSpock allows $!possiblyNull, and the addition of the ! 
suppresses output of warnings.

(Additionally, iSpock allows customization of the comment
characters around/in-front-of warnings/errors that are
printed.)

I think the per-variable suppression of warnings is absolutely
needed.  Comment-customization is just plain nice to have.

	-bob