Fixes a number of important bugs, recommend all to update:
Overview of changes in lightdm 1.0.2
* Fix daemon from blocking if Accounts Service does not exist
* Fix greeter log file not being written
* Don't set LANG environment variable if using Accounts Service.
* Fix gdmflexiserver not working due to it not being in PATH
* Don't authenticate the greeter user
* Allow greeters to be disabled in configure flags
* Fix over allocation of read buffer in greeter protocol
* Make sure objects are cleaned up on exit
* Fix minor memory leaks
* Fix hugely oversized allocation in greeter buffer. Can trigger
crashes when entering very long passwords.