Critical path analysis update

The implementation of the prototype of the critical path analysis is underway. The data structure required to hold the mapping between nodes and system resource is now completed. The graph library jgrapht has been replaced by JUNG. This choice has been made because of the simpler usage of this new library. A trace library widget has been implemented. It allows to import traces in batch such that it's quicker to open a series of traces. On this infrastructure, the process hierarchy has been retreived as a test bench. It shows that the current datastructure should be is appropriate to achieve the demonstration in december.