FIXED BUG in initialisation of fullLength when reading from file. In case of no sequence and nodes provided, was not getting correctly the maximum value for contacts. Now using the method getMaxContact from new class ContactList
NEW FUNCTIONALITY in Graph:
-New member variable modified
-New methods addEdge, delEdge, restrictContactsToMaxRange, restrictContactsToMinRange, getContacts, getNodes, copy
-Improved slightly the implementation of getEdgeNbh 
FIXED BUG in initialisation of fullLenght when reading from file. In case of no sequence and nodes provided, was not getting correctly the maximum value for contacts. Now using the method getMaxContact from ContactList
New class ContactList
NEW FUNCTIONALITY in Graph:
-New member variable modified
-New methods addEdge, delEdge, restrictContactsToMaxRange, restrictContactsToMinRange, getContacts, getNodes, copy
-Improved slightly the implementation of getEdgeNbh 
New method getRange in Contact