When a new task is added into the workflow, don't restart computations from the beginning of the workflow

[madruon]

Currently, tasks are run from the beginning of the workflow until the added task. Computation time can be decreased if only the new task is run. To do that, in the CWorkflowRunManager::runSequentialTask(const WorkflowVertex &taskId) method, change the line

m_workflowPtr->runTo(taskId);

by

m_workflowPtr->runFrom(taskId);