Automatic merge of T1.5.1-969-g2319f7f14 and 15 pull requests

- Pull request #799 at dfc715e: Consolidated wind simulation
- Pull request #839 at d00beb9: First phase of https://blueprints.launchpad.net/or/+spec/additional-cruise-control-parameters
- Pull request #876 at f92de76: docs: add source for documents previously on website to source Documentation folder
- Pull request #882 at 48aa537: Blueprint/train car operations UI window
- Pull request #891 at 9a1d6b2: Auto save
- Pull request #892 at 1f5ba4c: Signal Function OPP_SIG_ID_TRAINPATH
- Pull request #896 at 5866028: First implementation of https://blueprints.launchpad.net/or/+spec/specific-sounds-for-ai-trains
- Pull request #900 at c27f32d: DMI updates
- Pull request #903 at 4742fa3: Downloading route content (Github, zip)
- Pull request #912 at 0cb07c2: New Triple Valve Features Vol. 2
- Pull request #918 at c46eb0d: Manual - News topics updated since 1.5.1
- Pull request #919 at 26cc6a8: Added mouse wheel support for controls which can be moved by pressing t…
- Pull request #922 at abe2e52: Autopilot for timetable mode
- Pull request #923 at 4c27204: Add curve squeal to route
- Pull request #943 at a0ffa96: Dynamic Brakes Behavior & Display Improvements

Author: openrails-bot