only require core for bin/rib, not for Rib.shell, see:

at first i want to give people core plugins automatically
if you're not using any plugin. so that using `rib` directly
would give you an irb like session. but this is buggy :(

if there's a program:

    require 'rib/more/anchor'
    Rib.anchor 123

then this would crash, because we ended up with plugins:
(crash reason is that Anchor is not overriding Underscore!)

    [Rib::Anchor, Rib::Underscore]

but it should be:

    [Rib::Underscore, Rib::Anchor]

or merely:

    [Rib::Anchor]

we can't really detect if we would want core plugins when
calling `Rib.shell`, so this is too messy!

thanks andrew

bin/rib

@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
 
 require 'rib/runner'
+require 'rib/core'
 Rib::Runner.run(ARGV)

lib/rib.rb

@@ -35,11 +35,7 @@ def home
   # need a clean shell which does not load rc file, use Shell.new instead.
   def shell
     shells.last || begin
-      if config_path
-        require_config
-      else # for those who don't have a config, we use core plugins
-        require 'rib/core'
-      end
+      require_config if config_path
       (shells << Shell.new(config)).last
     end
   end