if one script fails (in multi), ensure that only that object's pins are reset

[stevieb9]

Currently, the entire shared memory is wiped, which will clearly break other separate objects in other processes.

[stevieb9]

Perhaps each Pi object should have a checksum created on initialization, stored both in the object as well as the shared memory, and each pin registered should be associated with that Pi checksum, so only that object's pins are cleaned up on failure or closure.

[stevieb9]

One way to generate a random identifier:

perl -wMstrict -MDigest::MD5 -E 'say Digest::MD5::md5_hex(rand)'

4f08e6d04f61b97ac8858ce11cf230d1

[stevieb9]

When an object fails to instantiate due to conflicting pins, don't delete the entire shared memory.