Create example env lazily to avoid spurious warnings. Also allow example-import-only to disable importing of the default env. Fixes issue #390.
Create example env lazily to avoid spurious warnings.
Also allow example-import-only to disable importing of the default env.
Fixes issue #390.

holmescn/chibi-scheme,holmescn/chibi-scheme,holmescn/chibi-scheme,holmescn/chibi-scheme,holmescn/chibi-scheme