Map script inside a group still buggy.

I do not know if it was fixed or not but the behaviour is different this time.

1 Create mapscript component and group it.
2 ctrl-c ctrv-v on group.
3 Save filter and reopen it.
4 Deleting on of the groups produces following crash.

Controls::Control] Exception occured while processing window message 0x00000100(WM_KEYDOWN) (0x0000002E 0x01530001) for window 000808E0/000808E0, control: <class Controls::FilterEditor>@2921CFA8.
[Controls::Control] Exception occured while processing window message 0x00000111(WM_COMMAND) (0x0000F9A8 0x00080530) for window 000A01C8/000A01C8, control: <class Controls::Panel>@0FC08938.
[Controls::Control] Exception occured while processing window message 0x00000202(WM_LBUTTONUP) (0x00000000 0x00170040) for window 00080530/00080530, control: <class Controls::PushButton>@1051F9A8.
Exception caught at thread 000018DC 'Application':
<class XFW::ArgumentError> Failed to find class info for missing component class 'ScriptMap01'.

<unknown file>(0) : <unknown function>()+0 at 006D605A in Filter Forge x86.exe
CONTEXT_CONTROL: CS:EIP 0023:74D0C41F, SS:ESP 002B:01C5530C, EBP 01C5535C, FLAGS 00000206
CONTEXT_INTEGER: EAX 01C5530C, EBX 01C553C0, ECX 00000003, EDX 00000000, ESI 00B38194, EDI 01C5539C
CONTEXT_SEGMENTS: DS 002B, ES 002B, FS 0053, GS 002B

This is because our Script components don't properly support instancing yet. Fixing this will take some time.