Up versions to WLT v1.5.9 in preparation for release. (microsoft#291)

Add sample for vehicle type configuration (microsoft#267)

* Add sample scene for camera locked to vehicle moving through coordinate space.

* Limit AlignSubtree in vehicle sample to rotation in the horizontal plane.

* Add namespace and copyright notice.

Raise creation point of underlying anchors (microsoft#244)

* Move anchor creation to camera position from legacy position 1 meter down.
Fix compatibility bug with ASA 2.11 Read (Search unaffected).
Bump version to v1.5.7.

* Add option to zero out pitch and roll from correction computed by FrozenWorldEngine.

Update to ASA v2.11 (microsoft#241)

* Update to ASA v2.11.0.
Also prepares for upgrade to ASA v2.12.0 (removing workarounds).
Also adds iOS ASA reference.

* Update package generation for creating WLT v1.5.6.

Backward compat for Unity 2018 .NET backend (microsoft#218)

* Remove unused using that Unity added.

* Bump patch version to v1.5.4.

* Modify StreamWriter usage to be backward compatible to deprecated .NET backend (Unity 2018).

* Prep packaging files for v1.5.4.

* Fix case where sometimes ASA anchors fail because they aren't ready, by adding delay by 1 frame between create and access.

* Missing paren.

Tuples (microsoft#214)

* Remove dependency on tuple from SpacePinVisualizer.

* Bump patch version to 1.5.3.

* Update packaging files for v1.5.3, and lower Unity dependency for core and examples to U2018.4.

* Minor documentation updates (esp ASA only targets ARM64 on HL2).

* Delete unused documentaton icons.

Support for Holographic Remoting (microsoft#213)

* Make XR Anchor Manager startup async so it can wait for XR startup if necessary.

Also, some minor no-op changes to suppress warnings.

* Expand remoting support to pre-Unity2020.

* Bump patch version to 1.5.2.

* Port ARF fix back to ARF2019.

* Make AlignSubtree component smarter about auto-save and load.

* Update publishing files to v1.5.2.

WLT quiet mode (microsoft#209)

* First pass making all WLT logging mutable.

* Move to taking advantage of ConditionalAttribute.

* Fix SpongyAnchorARF to return spongy pose when not applying adjustment.

* Update packaging to v1.5.1.

* Disable space pin binder file logging by default.

Support local world locking (microsoft#202)

* Up-port local application of base world locking to subgraph in scene hierarchy from Samples/AlignSubtree.

* Update UPM generation files for version 1.5.0.

* Don't modify the camera hierarchy if adjustments aren't being applied by the WLT.

Somehow missed these files with last checkin. (microsoft#194)