#142 "removed" signatures are not processed

[Michiel Hendriks]

See StarLight\Examples\TestCases\ErrorFilterTest

There is only a single filter, an error filter, on the method f2. The result program should raise an exception when f2 is called. However, f2 is currently simply executed.

The weave spec only includes filter code for methods with the state "normal" and "added". Sign gave the f2 method the status "removed".