Optimise string handling in ansible.utils._clean_data
Fix copy/paste error
Test escaping strings with two variables
Switch cStringIO to StringIO for unicode support

The performance difference isn't too bad
Pre-load whole string and use seek to alter tags
Merge branch 'optimise_utils_clean_data' of https://github.com/leth/ansible into leth-optimise_utils_clean_data
Merge branch 'leth-optimise_utils_clean_data' into devel