Allow installation into Ships/Script

[HebaruSan]

Problems

• kOS stores scripts in the Ships/Script folder under the game root. Currently CKAN doesn't allow this, and Add SpaceCore kOS Script Pack from SpaceDock NetKAN#7967 is in stasis because it needs to install kOS scripts to that folder.
• ShipSaveSplicer is being installed into GameData/veSplicer because it starts with Ships

Changes

• Now we allow installation into Ships/Script, including creation of new directories.
  Since this requires an update of the schema, the next release of CKAN will need to be v1.29.0 if this is merged.
• Now we require a path to start with Ships/ with a slash to trigger that truncation, so ShipSaveSplicer will be installed correctly.
  Fixes ShipSaveSplicer installed into wrong directory #3187.

[DasSkelett]

With spec version <v1.12 it first outputs 1188 [1] FATAL CKAN.NetKAN.Program (null) - spec_version v1.12+ required to install to Ships/ with path, and only with a spec version v1.12 <= x < v1.29 it outputs the new warning.
Should we reorder the checks, or maybe narrow down the first one so it only triggers for Ships/SPH and Ships/VAB?

[HebaruSan]

Fair point, moved the 1.29 check before the others.

[HebaruSan]

Just discovered this breaks typical netkans. Need to investigate (later).

$ ../CKAN/_build/netkan.exe NetKAN/MissingRobotics.netkan 
4985 [1] FATAL CKAN.NetKAN.Program (null) - GameData/Missing_robotics is not an absolute path

... this is a bit tricky. InstallableFile.destination is supposed to be an absolute path into the KSP dir, but it's relative if KSP.gameDir is /, because KSPPathUtils.NormalizePath does .TrimEnd('/'), which turns / into the empty string. NormalizePath seems like the part that's doing something wrong to me, since / and the empty string do not represent the same paths at all...

[HebaruSan]

That stuff should be fixed with the latest changes.

[DasSkelett]

Unleash the kOS scripts!