Raise TypeError from #singleton_class
Allow instance_exec for Symbol and Numeric
Disallow singleton methods for Symbol and Numeric
Numeric#singleton_method_added

Specs untagged:

Numeric#singleton_method_added
- raises a TypeError when trying to define a singleton method on a Numeric
Forbid extnding Fixnum ans Symbol Objects
We cann't use #exnted
add String#scan
fix translation
tag some failing specs
BasicObject includes itself as a constant

Specs fixed:

BasicObject
- includes itself in its list of constants
Fixed constant resolving

Specs fixed:

BasicObject
- raises NameError when referencing built-in constants
Fixed defined? for constants

Specs fixed:

BasicObject
- does not define built-in constants (according to defined?)
Break if not Class
Move methods from Object to kernel

Specs fixed:

BasicObject subclass
- contains Kernel methods when including Kernel
Merge pull request #706 from krekoten/move_methods_to_kernel

Move methods from Object to Kernel
Untag more specs
Merge pull request #707 from jstepien/untag-more-specs

Untag more specs
Hash compares
Merge pull request #708 from kostya/hash_cmp

Hash compares
fix Hash#replace