added some features for transition to 2.6

Hi, love your work on this plugin. It's clean and to the point.

I have added some modifications:

* a filter to change the arguments supplied to wp_generate_password. This seems a little less drastic that to use the pluggable function of wp_generate_password
* Updated readme / plugin header
* Activated text-domain and placed languages files in a languages folder

I'm available for comments or whatever :)