Allow specifying lines with no expected coverage

[GoogleCodeExporter]

There can be lines in the code who will never be covered, because of spurious 
compiler code generation or other special code situations.

One possible solution would be to detect special comments on a line, and when 
encountered, not report the line as not covered.

For instance in:

   procedure MyProc;
   begin
      ThisProcedureAlwaysTriggersAnException;
   end; {expected coverage issue}

the compiler will generate code for the 'end;', which can never be reached.
Other than spurious codegens, such cases can happen in other optimization 
scenarios where the compiler doesn't keep up.

Original issue reported on code.google.com by zar...@gmail.com on 22 Oct 2010 at 1:28