Change argument Proc to #call defined object

[osyo-manga]

Summary

Change argument Proc to #call defined object.
This is the same as the behavior of Readline.

Expected behavior

class DefineCall
  def call; end
end

# OK
Readline.completion_proc = DefineCall.new

# OK
Reline.completion_proc = DefineCall.new

Actual behavior

class DefineCall
  def call; end
end

# OK
Readline.completion_proc = DefineCall.new

# Error: ArgumentError
Reline.completion_proc = DefineCall.new

Changed methdos

• Reline.completion_proc=
• Reline.output_modifier_proc=
• Reline.prompt_proc=
• Reline.auto_indent_proc=
• Reline.dig_perfect_match_proc=