major clean for rb/py interfaces

* rm Lib-interface
* unify filenames for config and test
* rm pre-build wrapper code - now SWIG is always needed

interfaces/python/testLib.py

-import CdiLib
-ifile = "../testdata/mulval.nc"
-streamID = CdiLib.streamOpenRead(ifile)
-vlistID  = CdiLib.streamInqVlist(streamID)
-nvars    = CdiLib.vlistNvars(vlistID)
-for i in range(0,nvars):
-  print(CdiLib.vlistInqVarCode(vlistID, i))
-
-CdiLib.streamClose(streamID)

interfaces/ruby/extconfLib.rb

-require 'mkmf'
-load "extconf.rb"
-$libs = append_library($libs, "stdc++")
-$srcs = %w[cdilib_wrap.c]
-$objs = %w[cdilib_wrap.o]
-create_makefile('CdiLib')

interfaces/ruby/testLib.rb

-require './CdiLib'
-include CdiLib
-ifile = ARGV[0].nil? ? "../testdata/mulval.nc" : ARGV[0]
-streamID = streamOpenRead(ifile)
-vlistID  = streamInqVlist(streamID)
-nvars    = vlistNvars(vlistID)
-(0...nvars).each {|i|
-  print vlistInqVarCode(vlistID, i).to_s + ' '
-}
-puts
-streamClose(streamID)