Escape the source container and object name to be copied from

[cgunther]

Rackspace seems to 500 if your source object name has unicode characters that are not escaped.

I tried to get the test suite running locally, but it's giving a the following error:

LoadError: cannot load such file -- fog/schema/data_validator
  tests/helpers/formats_helper.rb:1:in `require'
  tests/helpers/formats_helper.rb:1:in `<top (required)>'

I've been running this patch in production for 3 months without issue.

Fixes #6.