PLOT: rem. prefixes of custom plots "z.runtime"..
PLOT: now checks if custom nvl/dist list is empty
PLOT: added custom mv_ and stat_ plots
PLOT: renamed Plotting.plotCustomValues-method
PLOT: added statistics.* & runtimes.* to plots

- custom value plots may now also add statistics.* and runtimes.* values
by using these prefixes
PLOT: added domains to config
PLOT: renamed some prefixes for custom plots
PLOT: rem. prefixes of custom dist/nvl plots
PLOT: added value checks in custom dist/nvl plots
PLOT: fixed nullpointer exception in custom plots

- the nullpointer exception was thrown when a valueplot had a
distribution or nodevaluelist added to its values
- values will now be checked to be null and a warning will be printed if
so
PLOT: added runtime plot wildcards
PLOT: added gen/met runtimes domains and *
PLOT: added custom value plot wildcards for stats
PLOT: updated general/metric runtime plots
PLOT: added custom statistic plot wildcards
PLOT: added new plot attributes in plotconfig
PLOT: full support for new plot attributes
PLOT: plot class cleanup
PLOT: minor code cleaning