Some improvements so the container can run all its processes without root priveledges

[scufre]

These includes the following changes aimed to run the container process without requiring root privileges:

• Fix the Dockerfile so the default argument is the full path of the run.sh script so the docker-entrypoint.sh script catches it and drops privileges.
• Changed to use supercronic instead of cron which doesn't require root.
• Updated so the mysql daemon now runs under the www-data account
• Added some setup to the docker-entrypoint.sh script to adjust file permissions
• Changed daemons to log into the /var/log/ampache directory so it can be used as a volume

[lachlan-00]

that's cool, i've never heard of supercronic before. i work during the week sol i'll check it out then and merge

[KaeTuuN]

@scufre Does this still work? Would be great to see it merched!