Haizea

A few minor changes so Haizea will work with Python 2.4

Kludge so logging will work before Manager is fully initialized.

Updated configuration file parser; datafile is now in [accounting], not in [general]

Switched to a saner implementation for Singleton classes. Required multiple changes all around (which had the indirect side effect of making constructors less dependent on the get_config() function)

Documented accounting module. Minor fixes to default probes.

Miscellaneous pylint-induced code cleanup.

Fixed whitespace that, while ok to Python, made epydoc barf.

Minor fixes for issues detected when running unit tests after last commits. Also removed several print statements that shouldn't be there.

Modified the accounting code so information is gathered using "probes" instead of inserting hardcoded statements throughout the Haizea code. Now, collecting additional information involves writing a pluggable probe, instructing the accounting module when the probe must be run (currently this can be at every timestep, when a lease is requested, or when a lease is done). Thus, gathering additional information doesn't require modifying the core Haizea code....

Made persistence configurable. Documented persistence code.