Improve !remind time detection (allow e.g. "!remind 7d-2h")

CHANGELOG

@@ -1,7 +1,7 @@
 v0.3 (unreleased):
 
 - Copyvio detector: improved sentence splitting algorithm.
-- IRC: Added !remind all.
+- IRC > !remind: Added !remind all. Improved time detection.
 - IRC: Improved detection of maximum IRC message length.
 - IRC: Improved some help commands.
 

earwigbot/commands/remind.py

@@ -78,13 +78,11 @@ class Remind(Command):
             else:
                 raise ValueError(node)
 
-        if arg and arg[-1] in time_units:
-            factor, arg = time_units[arg[-1]], arg[:-1]
-        else:
-            factor = 1
+        for unit, factor in time_units.iteritems():
+            arg = arg.replace(unit, "*" + str(factor))
 
         try:
-            parsed = int(_evaluate(ast.parse(arg, mode="eval").body) * factor)
+            parsed = int(_evaluate(ast.parse(arg, mode="eval").body))
         except (SyntaxError, KeyError):
             raise ValueError(arg)
         if parsed <= 0: