Proc#=== is alias for Proc#call

Fixes specs:

Proc#===
- invokes self
- sets self's parameters to the given values
- can receive block arguments

Proc#=== on a Proc created with Proc.new
- replaces missing arguments with nil
- silently ignores extra arguments
- auto-explodes a single Array argument

Proc#=== on a Proc created with Kernel#lambda or Kernel#proc
- ignores excess arguments when self is a proc
- substitutes nil for missing arguments when self is a proc
- treats a single Array argument as a single argument when self is a lambda
- treats a single Array argument as a single argument when self is a proc
Proc#yield is an alias for Proc#call

Fixes specs:

Proc#yield
- invokes self
- sets self's parameters to the given values
- can receive block arguments

Proc#yield on a Proc created with Proc.new
- replaces missing arguments with nil
- silently ignores extra arguments
- auto-explodes a single Array argument

Proc#yield on a Proc created with Kernel#lambda or Kernel#proc
- ignores excess arguments when self is a proc
- substitutes nil for missing arguments when self is a proc
- treats a single Array argument as a single argument when self is a lambda
- treats a single Array argument as a single argument when self is a proc
Tagged failing spec for Proc#===
Merge pull request #613 from krekoten/proc_call

Alias `Proc#yield` and `Proc#===` to `Proc#call`