-P plus -v then show prereqs verbose

if command line have `-P` and `-v` parameters, recursion show prerequires and show task define locations.


rake -P

    rake a1
    rake a2
        a1
    rake b1
    rake b2
        b1
    rake c1
        a2
        b2


rake -P -v

    task  a1  ["bb/a1.rake:6", "bb/a1.rake:15"]
    task  a2  ["bb/a2.rake:4"]
      task  a1  ["bb/a1.rake:6", "bb/a1.rake:15"]
    filetask  b1  ["bb/b1.rake:5"]
    task  b2  ["bb/b1.rake:10", "/tmp/aa/Rakefile.rb:53"]
      filetask  b1  ["bb/b1.rake:5"]
    task  c1  ["/tmp/aa/Rakefile.rb:56", "/tmp/aa/Rakefile.rb:57"]
      task  a2  ["bb/a2.rake:4"]
        task  a1  ["bb/a1.rake:6", "bb/a1.rake:15"]
      task  b2  ["bb/b1.rake:10", "/tmp/aa/Rakefile.rb:53"]
        filetask  b1  ["bb/b1.rake:5"]