DAO: fix classnames in __init__

to make logging work again
UbikPeerDAO: fix syntax according to pylint.rc
CellService: multiple fixes and cleanups.

Now service and test work as required.
Testsetup: minor fixes
AFSConfig: load default configs only if

not config file is given on the command line.
Only load one config file at all.
If there is one i $HOME, do not load the system-wide config file
Executor: do not initialize logging.

this is done by BaseDAO and BaseUtil
BaseService: DNSConf is not a DAO anymore
FSsService: use common name for partition sizes
History: add support for outdated data

all overwritten data in the DB_CACHE will be copied
to "historical" tables.
These tables need to be vaccuumed by the application.
This can be controlled by two configuration options
--DB_HISTORY_NUM_DAYS : number of days an entry should stay
--DB_HISTORY_NUM_PER_DAY : how many entries per day of one
datapoint should stay in the DB