Remove if_ruby adapter

The list of things worse than if_ruby is pretty short, and does not
include if_pyth.

README.markdown

@@ -33,7 +33,8 @@ based on `target/repl-port`, otherwise it's just a `:Connect` away.  You can
 connect to multiple instances of nREPL for different projects, and it will
 use the right one automatically.
 
-The only external dependency is that you have Ruby installed.
+The only external dependency is that you have either a Vim with Python support
+compiled in, or `ruby` in your path. (Don't ask.)
 
 Oh, and if you don't have an nREPL connection, installing [classpath.vim][]
 lets it fall back to using `java clojure.main`, using a class path based on

autoload/nrepl/foreplay_connection.vim

@@ -198,51 +198,10 @@ let s:nrepl = {
       \ 'path': s:function('s:nrepl_path'),
       \ 'process': s:function('s:nrepl_process')}
 
-if has('ruby')
-ruby <<
-require 'timeout'
-require 'socket'
-class << ::VIM
-  def string_encode(str)
-    '"' + str.gsub(/[\000-\037"\\]/) { |x| "\\%03o" % (x.respond_to?(:ord) ? x.ord : x[0]) } + '"'
-  end
-  def let(var, value)
-    command("let #{var} = #{string_encode(value)}")
-  end
-end
-.
-
-function! s:nrepl_call(payload) dict abort
-  let payload = nrepl#foreplay_connection#bencode(a:payload)
-  ruby <<
-  begin
-    buffer = ''
-    Timeout.timeout(16) do
-      TCPSocket.open(::VIM.evaluate('self.host'), ::VIM.evaluate('self.port').to_i) do |s|
-        s.write(::VIM.evaluate('payload'))
-        loop do
-          body = s.readpartial(8192)
-          raise "not an nREPL server: upgrade to Leiningen 2" if body =~ /=> $/
-          buffer << body
-          break if body.include?("6:statusl4:done")
-        end
-        ::VIM.let('out', buffer)
-      end
-    end
-  rescue
-    ::VIM.let('err', $!.to_s)
-  end
-.
-  if !exists('err')
-    return nrepl#foreplay_connection#bdecode('l'.out.'e')
-  endif
-  throw 'nREPL Connection Error: '.err
-endfunction
-
+if !has('python')
   finish
 endif
 
-if has('python')
 python << EOF
 import vim
 import socket
@@ -295,7 +254,4 @@ EOF
   throw 'nREPL Connection Error: '.err
 endfunction
 
-finish
-endif
-
 " vim:set et sw=2:

doc/foreplay.txt

@@ -41,10 +41,8 @@ buffer and classpath.vim is installed, java (or $JAVA_CMD) is invoked
 directly, which can be quite slow depending on your setup.
 
 The only adapter shipped with foreplay.vim is for nREPL.  You need Ruby
-installed and either |if_ruby| or the ruby command in your PATH.
-Alternatively, if |if_ruby| is not available, it will attempt to use
-|if_pyth|. If neither exists, however, it will still attempt to use the ruby
-command in your PATH.
+installed and either |if_pyth| or the ruby command in your PATH.
+(This curious combination is an accident of history.)
 
 DOCUMENTATION                                   *foreplay-documentation*