Patch Notes: Fast shadows, without the flicker

Enhanced Lighting

The shadow cache is on again by default, so lamp-lit rooms such as taverns, shops and guild halls get their frame rate back.
Fixed the shadow flicker with Enhanced Lighting on Windows: a rapid, strobing flicker on some NVIDIA cards, and on others every shadow in a room blinking at once. It came from how the cached shadows were copied on Direct3D, not from the cache itself.
The "Shadow cache (faster, may flicker)" switch is gone from Enhanced Lighting. It is no longer needed.

Trees, bushes and rocks no longer stand on roads and tracks, and their branches no longer hang over them. This includes the 3D trees from Low Poly Trees.
Herb patches, ore veins on open stone and Motherlodes keep off the roads too.
Forests no longer grow across dirt tracks.
Settings › Clear roadsides (on by default). Off lets them grow up to the edge of the road, as Daggerfall does.

Where two climates meet, the land no longer changes along a straight line. The border wanders and breaks into patches about two hundred metres deep: grass thins out into sand, rock creeps into the woods, snow comes in drifts.
The trees follow the same border. Near it, each tree belongs to the climate of the ground it stands on.
The grass follows it too.
Settings › Blended climates (on by default). Off changes them at a straight edge, as Daggerfall does.

Both settings take effect when the world next loads. Online, both are always on, so everyone sees the same trees in the same places.

In winter, the trees of a wood are cover the way they are the rest of the year: enemies hide behind the trunk and under the crown.

VERGE1 + ECOTONE1: the wild keeps off roads and tracks; climates meet at a wandering, patchy border by @Lattymoy in #660
CACHE-COPY: the shadow flicker was the cache's copy on Direct3D - fixed, and the shadow cache on by default again by @Lattymoy in #661

Full Changelog: app-v0.1.6678...app-v0.1.6690