more robust slave description

also enforce slave name

emacs/slaves.py

@@ -10,16 +10,18 @@ def getSlaves():
     slaves = []
 
     for s in os.listdir(_slaves_defs_dir):
-        f = file(os.path.join(_slaves_defs_dir, s, 'slave.yaml'), 'r')
-        d = yaml.load(f)
-        if not d.has_key('name') or not d.has_key('password'):
-            continue
+        fpath = os.path.join(_slaves_defs_dir, s, 'slave.yaml')
+        if os.path.exists(fpath):
+            f = file(fpath, 'r')
+            d = yaml.load(f)
+            if not d.has_key('password'):
+                continue
 
-        properties = {}
-        if d.has_key('features'):
-            properties['features'] = d['features']
+            properties = {}
+            if d.has_key('features'):
+                properties['features'] = d['features']
 
-        slaves.append(BuildSlave(d['name'], d['password'],
-                                 properties=properties))
+            slaves.append(BuildSlave(s, d['password'],
+                                     properties=properties))
 
     return slaves