stators texture mapping updated, matching paintability of vanilla motors

Changes summary:
- fixed rotor displacement issue

Complete changes:
- Rotor Displacement in models reduced to 1µm (almost zero) in order to match the new absence of .sbc setting to balance it. (bug: <RotorDisplacementInModel> no longer working as expected since 1.053.013)
- All motors' displacement now default to zero, which is also the new true zero (see above)
- Large versions can now be set between -25 and +25cm for compatibility with future updates of other mods

added small ship version
added new blocks to Small Blocks g menu category
fixed material for stator construction stage 2
tweaked torque, component costs and construction times to match motors size

first release