use global GrumbleError for web exceptions

modules/weather.py

@@ -9,7 +9,7 @@ http://inamidst.com/phenny/
 
 import re, urllib.request, urllib.parse, urllib.error
 import web
-from tools import deprecated
+from tools import deprecated, GrumbleError
 
 r_from = re.compile(r'(?i)([+-]\d+):00 from')
 
@@ -29,9 +29,6 @@ def location(name):
     lng = results['geonames'][0]['lng']
     return name, countryName, lat, lng
 
-class GrumbleError(object): 
-    pass
-
 def local(icao, hour, minute): 
     uri = ('http://www.flightstats.com/' + 
              'go/Airport/airportDetails.do?airportCode=%s')