Fix 'Err: fatal: not a git repository' when switching git work tree
Invalidate work tree cache dir when switch have been failed. For example if original git-repo linked with this work tree has been gone.
Fixes for windows
- Support for symlinks in the git repo.
- Fix introspection.
- Fix wrong line breaks in the files added by git mappings from Windows host system.
- More e2e tests.
- Small docs fixes.