added a function to remove spaces at the beginning and the end of node and arc names
remove the temporary policy2 object
integrated read me and policy file in Xcode project
Changed name of graph.cpp and graph.h in tinygraphdb.cpp and tinygraphdb.h
made graphdbinterface and recoded the intern representation of data
some cleaning
Added the newNode function to GraphDb.
A new node does not have a unique_id -> the database will check the number of node and give a unique_id to a new node.

save in fame instead of "test.txt" :)
type is written (type)
added function to get nodes
added getArInOfType() and getArcOutOfType() methods to the Node class
fromNode in Arc class is no more const -> it is a bad thing but I need it
changed policy.txt in database.txt
the graph database is working... not optimized at all git status