removed some trivial spaces from output
modified the way accept-charset is added
Documented a second argument in the decode() function for the Encryption Class
Documented a second argument in the decode() function for the Encryption Class
a series of clarifications of the docs
increased randomness of file name used in is_really_writable()
Made get_mime_by_extension() case insensitive.
uncommenting a function
Deprecated the dohash() function in favour of do_hash() for naming consistency.
added translation of fields passed as validation rule parameters
numerous changes from DIR_WRITE_MODE to FILE_WRITE_MODE
chmod operations on files were using the DIR_ constant permisisons
Modified inflector helper to properly pluralize words that end in 'ch' or 'sh'

http://codeigniter.com/bug_tracker/bug/9384/
added hyphens to allowed characters in GET keys and vals in submitted URLs in xss_clean()
incorrect variable name in the smiley helper js
margin fix
non-backwards compatible change to get_dir_file_info() for performance reasons, as well as fixing recursive bug
fixed bug where active record override wasn't being honored properly
tweak in database() to match change to $active_record variable
Fixed an error in the Zip library that didn't allow downloading on PHP 4 servers.
Fixed a language key in the profiler: "profiler_no_memory_usage" to "profiler_no_memory".