Fixed typos on validates_numericality_of all over AR validations and …

…callbacks guide

railties/doc/guides/source/activerecord_validations_callbacks.txt

@@ -223,7 +223,7 @@ end
 
 This helper has an alias called +validates_size_of+, it's the same helper with a different name. You can use it if you'd like to.
 
-=== The +validates_numericallity_of+ helper
+=== The +validates_numericality_of+ helper
 
 This helper validates that your attributes have only numeric values. By default, it will match an optional sign followed by a integral or floating point number. Using the +:integer_only+ option set to true, you can specify that only integral numbers are allowed.
 
@@ -232,12 +232,12 @@ If you use +:integer_only+ set to +true+, then it will use the +$$/\A[+\-]?\d+\Z
 [source, ruby]
 ------------------------------------------------------------------
 class Player < ActiveRecord::Base
-  validates_numericallity_of :points
-  validates_numericallity_of :games_played, :integer_only => true
+  validates_numericality_of :points
+  validates_numericality_of :games_played, :integer_only => true
 end
 ------------------------------------------------------------------
 
-The default error message for +validates_numericallity_of+ is "_is not a number_".
+The default error message for +validates_numericality_of+ is "_is not a number_".
 
 === The +validates_presence_of+ helper
 
@@ -325,7 +325,7 @@ As stated before, the +:on+ option lets you specify when the validation should h
 ------------------------------------------------------------------
 class Person < ActiveRecord::Base
   validates_uniqueness_of :email, :on => :create # => it will be possible to update email with a duplicated value
-  validates_numericallity_of :age, :on => :update # => it will be possible to create the record with a 'non-numerical age'
+  validates_numericality_of :age, :on => :update # => it will be possible to create the record with a 'non-numerical age'
   validates_presence_of :name, :on => :save # => that's the default
 end
 ------------------------------------------------------------------