Option to export large and small blocks with the same absolute size

[harag-on-steam]

Players often want to use a large block model with their small ship grids. This option would automate the export for that.

Necessary changes:

• separate block dimensions for the small block version (ExportSettings, SESceneProperties, DATA_PT_spceng_scene)
  • reason: the model might occupy less than the full large block dimensions
  • requires an offset relative to the large block center that translates into a <ModelOffset> in the block-definition
  • drawing of the secondary small dimensions bounds
• re-scaled mount point calculation for the small block-definition (mount_point_definitions() or its callers)
  • also needs to honor the offset
• no model export for the small version, instead large block models are referenced in the block-definition (BlockExport, BlockDefinitionNode, MwmFileNode).

[mafoo]

when rescaling the mount point calculations there seems to be inconsistencies on a Z offset of 1 left side has scaled fine with it's offset, but right side is wrong. however a Y of 0.8 is working fine!

[mafoo]

I suspect because the mount points need to be calculated of the cubesize in small is where my downfall is happening, although some need to multiply by 5 because they are 5 wide others being 1 (or 2 or 3) need to be dealt with in a relative way