Properties 1C/1D are supported only by OpenTTD 14+.
Also using C5xx range in prop 1C is not supported by OpenTTD.
With this PR C4xx/C5xx are always used for IDs<256 without using properties 1C/1D, and for IDs>=256 the properties are used and the strings are in DCxx range.
Properties 1C/1D are supported only by OpenTTD 14+. Also using C5xx range in prop 1C is not supported by OpenTTD.
With this PR C4xx/C5xx are always used for IDs<256 without using properties 1C/1D, and for IDs>=256 the properties are used and the strings are in DCxx range.
Fixes #311