[Lazarus] New BuildMode GUI + NewBuildModeWindow define

[Juha Manninen]

Hi

I finally got the new GUI in project options for build modes working.
To test it, build Lazarus with define "NewBuildModeWindow".
There is no added functionality yet, only the GUI is more intuitive.
The new modal dialog for managing build modes is visually "above" the
actual settings, thus indicating it affects them all.

The dialog has a copy of the project's build modes whch are assigned
back and forth.
New Assign methods had to be made. I struggled to get rid of all
SIGSEGVs for some time.
Now it does not crash but I didn't test if all the settngs are carried
correctly with the modes.

Could somebody please test it and comment.

Mattias may want to look at the code, too.
There is one techncal detail: project options dialog works directly
with Project1.BuildModes.
If the user clicks Cancel, the modes are restored from a backup copy.
IMO a cleaner way is to work on a copy and then assign if the user clicks OK.
Is there some technical reason against it?

Regards,
Juha