Automatic merge of T1.5.1-1695-gade019506 and 16 pull requests

- Pull request #570 at f11a428: glTF 2.0 support with PBR lighting
- Pull request #900 at 4629736: DMI in 3D cab + two more dials
- Pull request #1030 at d3ae4a2: Refactor settings, in prep for settings exporter
- Pull request #1045 at cc4d53c: Bugfix: Empty Start Time for Explore, and other issues loading from Menu Selection and Content Routes
- Pull request #1052 at 3b5cb90: Content Manager: Add axle count, and lowest derail force
- Pull request #1062 at b96d6fa: Train Forces popup Window.
- Pull request #1064 at 52410f9: Add Train Info tab to Help window (F1)
- Pull request #1066 at 62c89c1: Log derailment, using TraceInformation.
- Pull request #892 at 1f5ba4c: Signal Function OPP_SIG_ID_TRAINPATH
- Pull request #896 at 335f998: First implementation of https://blueprints.launchpad.net/or/+spec/specific-sounds-for-ai-trains
- Pull request #1000 at d8d9709: Locomotive operation from control car
- Pull request #1049 at 6a0c471: Re-organise document storage and access
- Pull request #1057 at 254b6d4: Switchable brake system
- Pull request #1069 at 3f153f0: Mouse wheel control only with Alt – Followup for #1051
- Pull request #1070 at f818e40: Fix a NullReferenceException in TCS scripts
- Pull request #1055 at 5c78967: Route Based TTrack Sounds

Author: openrails-bot

Source/Documentation/Use this folder to store.txt

@@ -1,5 +1,5 @@
 In Source\Documentation\ to store source for documents useful in running Open Rails.
-This applies to core Open Rails and also to non-core (or "contributed" programs.
+This applies to core Open Rails and also to non-core (or "contributed") programs.
 
 They should be MS Office or OpenOffice format and will be processed to PDF format which is distributed as part of the installation and available to users in the drop-down Menu > Documents