Automatic merge of T1.5.1-1692-g8b2dd97c0 and 16 pull requests

- 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 5bbc476: Content Manager: Add axle count, and lowest derail force
- Pull request #1062 at 3b18c48: Train Forces popup Window.
- Pull request #1064 at 9b3415e: 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 #1000 at d8d9709: Locomotive operation from control car
- Pull request #1029 at 92c74ef: Superelevation Follow Up Fixes
- Pull request #1057 at 50c3789: Switchable brake system
- Pull request #1065 at 409064d: Fix for PantographToggle sound event
- Pull request #1069 at ffd1af4: Mouse wheel control only with Alt – Followup for #1051
- Pull request #1055 at 90bbcff: Route Based TTrack Sounds
- Pull request #896 at f1681df: First implementation of https://blueprints.launchpad.net/or/+spec/specific-sounds-for-ai-trains
- Pull request #1049 at 4dd8c4f: Re-organise document storage and access

Author: openrails-bot

Source/Documentation/Keyboard Layout DE V1.1d.pptx

@@ -0,0 +1,15 @@
+In Source\Documentation\ store the source files for documents useful in running Open Rails.
+These will be processed to PDF format which is distributed as part of the installation and available to users in the drop-down Menu > Documents
+
+In Source\Documentation\Online store the source files for documents not used in running Open Rails.
+They should be MS Office or OpenOffice format and will be automatically processed to PDF format and stored on the website
+where they are available via a link in the drop-down.
+These include:
+- installation
+- translating
+- notifications
+- content creation
+- code-related
+- architecture
+
+