Don't crash on broken symlinks

Revert "Disable auto-import completions"

This reverts commit 862b2a3.

Disable auto-import completions

Until the performance sucks less. Fixes Dart-Code#1751.

Remove pink tint on UI guides

Implement custom tracking for edits

To reduce latency waiting for Flutter Outline updates.

Skip processing completion items for cancelled requests

May help with Dart-Code#1702.

Prepare v3.0.2

Prepare v3.0.1

Prepare v3.0

Revert to launch browser manually

This goes back to launching default browser and will need re-fixing, but we need to track down the VM service crashing and likely at least have a DevTools updated first.