plot_storage.rb checks for lack of logs now before trying to plot
Added validator to runner
Workflows logging fixed. Job toString method.
Logging termination only for started jobs.
VoidStorageManager logs transfer too.
Simulation validator fixed -> immediate transfers are not invalid.
Explanatory comments in void storage added.
Fixed broken test by Job.toString implementation
Merge pull request #125 from malawski/bugfix/logparser

Bugfix/logparser