#679 Few dvdstyler bugs in subtitle handling

[flanto]

In subtitle handling properties (see attachment) if you save settings clicking on "Use as predefined" button, then saved properties is misleaded and non correctly saved.
Additionally the poor large of spinboxes for color and margin settings doesn't allow to view 3 digits numbers, creating some confusion.
Furthermore if I chose any properties in dvdstyler project and change any type of setting, the program RELOAD intire movie, creating more cpu/io overload that do freeze system.

Best regards.