UniqueInstance: need event OnParamAdd

[AlexTP]

For CudaText I need the event which can change contents of cmd-line params before sending to first instance from 2nd instance (2nd instance gets params from cmd-line)

- for params beginning with '-' it does nothing
- for other params it will appeend current dir path (if it's file mask) but only if it's not full path name like "c:\dd\dd" or "\\unc\dir"

So event must be like
procedure (Sender: TObject; var AParam: string) of object;
 

[AlexTP]

Done in Github.