Specifying the option `--unsafe-links` (or `-l`) to `mpremote mount` will
allow symlinks to be followed in the local directory that point outside of
the base directory path.
For the unsafe case the `path_check()` method of `PyboardCommand` still
checks for a common path but without expanding symlinks. While this check
is currently redundant, it makes the purpose of the method clearer for
possible future uses or extensions.
This makes the auto soft-reset behaviour of mpremote more logical, and now
configurable via these new commands.
Signed-off-by: Damien George <damien@micropython.org>
