Merged last set of changes from original SVN location

lib/liquid/condition.rb

@@ -96,7 +96,7 @@ module Liquid
       left, right = context[left], context[right]
             
 
-      operation = self.class.operators[op] || raise(ArgumentError.new("Error in tag '#{name}' - Unknown operator #{op}"))
+      operation = self.class.operators[op] || raise(ArgumentError.new("Unknown operator #{op}"))
 
       if operation.respond_to?(:call)
         operation.call(self, left, right)

lib/liquid/context.rb

@@ -1,8 +1,5 @@
 module Liquid
   
-  class ContextError < StandardError
-  end
-  
   # Context keeps the variable stack and resolves variables, as well as keywords
   #
   #   context['variable'] = 'testing'

lib/liquid/errors.rb

@@ -1,7 +1,10 @@
 module Liquid
-  class FilterNotFound < StandardError
-  end
-
-  class FileSystemError < StandardError
-  end
+  class Error < ::StandardError; end
+  
+  class ArgumentError < Error; end
+  class ContextError < Error; end
+  class FilterNotFound < Error; end
+  class FileSystemError < Error; end
+  class StandardError < Error; end
+  class SyntaxError < Error; end
 end

lib/liquid/strainer.rb

@@ -24,7 +24,7 @@ module Liquid
     end
               
     def self.global_filter(filter)
-      raise StandardError, "Passed filter is not a module" unless filter.is_a?(Module)
+      raise ArgumentError, "Passed filter is not a module" unless filter.is_a?(Module)
       @@filters[filter.name] = filter
     end