dedicated user server

[mariux]

allow mxqd to be run as non root user
e.g. by adding an option --user=USER when run as root or by being able to start mxqd in setuid mode (for reading database credentials) and switch to and run as the user who executed mxqd.

this is based on issue #7 and may be nice to have in future releases so that a user can add more servers to calculate his jobs.

tasks:

• define tasks ;)

[donald]

This can now be achieved by using a combination of --tags and --prerequisites with mxqd and mxqsub.