== String#natcmp

  require 'facets/string/natcmp'

  "my_prog_v1.1.0".natcmp( "my_prog_v1.2.0").assert == -1
  "my_prog_v1.2.0".natcmp("my_prog_v1.10.0").assert == -1
  "my_prog_v1.2.0".natcmp( "my_prog_v1.1.0").assert == 1
  "my_prog_v1.10.0".natcmp("my_prog_v1.2.0").assert == 1
  "my_prog_v1.0.0".natcmp( "my_prog_v1.0.0").assert == 0

