Sensible default mask type

[Sybren Stüvel]

I'm using Hugin to create 360x180 equirectangular HDR panoramas. The mask type that I use most is "Exclude region from stack". Since this isn't the default mask type, I have to change the mask type for every mask that I add.

Either of those options would make me a happy man:
  - Remember the mask type of the lastly created/edited/selected mask and use that as the default for a new mask, or
  - Allow me to set a default mask type

[tmodes (tmodes)]

Implemented in changeset 2241e3220cc0

[Sybren Stüvel (sybren-stuvel)]

Thanks!