Don't repeat module name in class names

include/sardine.py

 import sys
 
 
-class SardinePluginError(Exception):
+class PluginError(Exception):
     pass
 
 
-class SardinePluginUsageError(SardinePluginError):
+class PluginUsageError(PluginError):
     pass
 
 
         method_n = "render_" + self.data.fmt
 
         def ex(__):
-            raise SardinePluginError("plugin method not defined: " + method_n)
+            raise PluginError("plugin method not defined: " + method_n)
 
         render_fn = getattr(self, method_n, ex)
         return render_fn()
                 module = imp.load_module(self.name, fh, modpath,
                                          (".py", "r", imp.PY_SOURCE))
         except IOError:
-            raise SardinePluginError("no such plugin: %s" % self.name)
+            raise PluginError("no such plugin: %s" % self.name)
         self.plugin = module.Plugin(self.plugindata)
 
     def _format_output(self, raw):
         try:
             self.subcommand = Subcommand(self.cmdargs, self.pluginpath)
             print self.subcommand.get_output()
-        except SardinePluginUsageError as e:
+        except PluginUsageError as e:
             msg = ("plugin usage: %s %s %s"
                    % (self.name, self.subcommand.name, e))
             self.die(msg, 11)
-        except SardinePluginError as e:
+        except PluginError as e:
             self.die(e, 10)