Support for other types of encoding

[hunterboerner]

Add support for Windows-1253 (greek). Currently, people using greek on windows which defaults to Windows-1253 cannot use KidsRuby.

C:\Users\Διαχειριστής>C:\KidsRuby\Ruby1.9.2\bin\ruby.exe C:\KidsRuby\KidsRuby\main.rb 
C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems/defaults.rb:43:in `exist?': "\x98" to UTF-8 in conversion from W 
indows-1253 to UTF-8 (Encoding::UndefinedConversionError) 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems/defaults.rb:43:in `default_path' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems.rb:752:in `path' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems/source_index.rb:59:in `installed_spec_directories' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems.rb:1051:in `source_index' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems/gem_path_searcher.rb:135:in `init_gemspecs' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems/gem_path_searcher.rb:14:in `initialize' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems.rb:1010:in `new' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems.rb:1010:in `searcher' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems.rb:207:in `try_activate' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:56:in `rescue in require' 
from C:/KidsRuby/Ruby1.9.2/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:35:in `require' 
from C:/KidsRuby/KidsRuby/main.rb:3:in `<main>'