Proc#call when self is lambda

Specs fixed:

Proc#call on a Proc created with Kernel#lambda or Kernel#proc
- raises an ArgumentError on excess arguments when self is a lambda
- raises an ArgumentError on missing arguments when self is a lambda

Proc#=== on a Proc created with Kernel#lambda or Kernel#proc
- raises an ArgumentError on excess arguments when self is a lambda
- raises an ArgumentError on missing arguments when self is a lambda

Proc#[] on a Proc created with Kernel#lambda or Kernel#proc
- raises an ArgumentError on excess arguments when self is a lambda
- raises an ArgumentError on missing arguments when self is a lambda

Proc#yield on a Proc created with Kernel#lambda or Kernel#proc
- raises an ArgumentError on excess arguments when self is a lambda
- raises an ArgumentError on missing arguments when self is a lambda
Merge pull request #718 from krekoten/proc_call

Proc#call when self is lambda