Remove KCODE from Ruby 1.9

KCODE is no longer supported in Ruby 1.9
Merge pull request #1 from phantomwhale/patch-1

Remove KCODE from Ruby 1.9
Fixes for use with Ruby 1.9: writes file name length to zip output stream in bytes instead of character count
bumped release version to 0.4.0: now works with ruby 1.9
ignoring rbenv config
Change EntryOpen to extend from StandardError, not Exception