native mode and scaler implementation

[max-verem]

this is updated set of patches that implements native mode selecting for PAL and 1080i25, and scaler setting

[fabled]

Thanks. The scaler stuff looks good.

But maybe I did not explain my thought clear enough on the native mode handling. I do not want "struct display_mode *native_mode;" added at all. The encoding_parameters.native_mode should be checked in the places where interlaced or convert_to_1088 are referenced. Duplicating the whole display_mode struct is bloat, when only one or two bits are affected -- and that overhead can be moved to code.

[fabled]

Scaler settings patch applied. Thanks.