Dynafed-storagestats

ADDED: '--version' flag.
FIXED: Some numerical stats were failing to be integer type.

CHANGED: For s3 boto3 clients, rather than creating the client right away,
it now first creates a session and from that the client. This is done
to make the execution multithreding 'safe'. Otherwise the sessoin is
global and was causing the execution to fail sometimes.
ADDED: "-f/--force" flag for "stats" sub-command to skip checks and force
stats check.
FIXED: Frequency issue that would constantly give wrong stats. Reason was that
the check was checking the connectionstats timestamp rather than the
storagestats.
CHANGED: How storage endpoints are read from the configuration files, moved
this selection process from get_storage_endpoints() to
get_storage_shares().
ADDED: Added checks and exception handling for when no endpoints are found.

ADDED: requirement of module 'prometheus_client'

ADDED: 'minio_prometheus' api for S3 endpoints.

ADDED: '-f, --force' flag to checksums put to force checksum metadata update.
FIXED: Issue when requesting storagestats with the list-objects API only 1000
objects would be returned for S3 and Azure classes.
FIXED: Typo on memcahced missing index log line.
REMOVED: Redundant memcahce empty checks.

ADDED: 'checksums' positional command with 'get' and 'put' sub-commands.
ADDED: base exceptions for checksum error and warnings.
ADDED: self contained get_object_checksum method for S3StorageShare.
ADDED: self contained put_object_checksum method for S3StorageShare.
CHANGE: Renamed set_object_metadata to put_object_metadata.
REMOVED: validate_checksum and deps, does note belong here.