Complete rewrite of dataset class, with (all) the necessary updates

system/project.py

@@ -13,8 +13,8 @@ class Project:
         self.name = name
         self.dim_names = []
         self._observers = {}
-        self.current_data=None
-        self.datasets=[]
+        self.current_data = None
+        self.datasets = []
         self.sel_obj = dataset.Selection()
         
     def attach(self,observer,key):
@@ -69,15 +69,11 @@ class Project:
     def add_dataset(self,dataset):
         """Appends a new Dataset to the project."""
         self.datasets.append(dataset)
-        for dim_name in dataset.ids.keys():
+        for dim_name in dataset.get_all_dims():
             if dim_name not in self.dim_names:
                 self.dim_names.append(dim_name)
+                self.sel_obj.current_selection[dim_name] = set()
 
-    def suggest_dim_name(self,dim_name):
-        """Creates an arbitrary unique name for a new dimension."""
-        while dim_name in self.dim_names:
-            dim_name = dim_name + "_t" 
-        return dim_name
         
     def object_at(self, path):
         "Returns the object at a given path in the tree."