Changelog:
2.1.4
more i18n fixes
2.1.3
finally (!) updated to use whatever value is used for the author/admin display name, as defined by "How to display name:" in the user's Profile.
2.1.2
tidied up i18n: made HTML form submit buttons translatable
2.1.1
more i18n
2.1.0
fresh i18n effort: /wp-content/subscribe2/ contains the .mo and .po files
both subscribe2.php and subscribe.php are translatable: place the appropriate .po file in the same directory as the source file for which it provides the translation
2.0.9
added editable subject line when sending an email to all subscribers
2.0.8
fixed batch logic
2.0.7
fixed broken comment
2.0.6
added $dreamhost manual override to force batched notification delivery
   thanks to Wade Emmert and Joe Mezzanini (http://themezz.com/) for their help
added Content-Type text/plain for plaintext mail delivery.
   thanks to Toto: 
   http://www.skippy.net/blog/2005/02/17/subscribe2/#comment-2059
2.0.5
added strip_tags() to plaintext email delivery, to remove HTML from post content
added date check to suppress sending notification on future-dated posts

2.0.4
fixed a typo which broke sending excerpts -- Thanks MarcoB!

2.0.3
added __() and _e(), plus subscribe2.po for localization
added stripslashes to (I hope!) all output
2.0.2
beautified output of categories to exlude

2.0.1
minor form fixes -- thanks Matt Read

2.0.0
major overhaul.
using new admin menu hooks
added Options page for web-based control of all messages
added HTML email support

1.5.6:
tightened up check against our own email; now only checks for an exact match against the admin email as defined in the blog options.
updated description of $categories_to_skip to indicate that category IDs should be entered

1.5.5:
fixed error handling when blank or invalid emails are passed to subscribe.php
fixed name used to sign email messages sent from subscribe.php: now using the admin account (user ID 1) email and nicename

1.5.4: 
fixed s2_style() to check for 1.5, which should fix it for 1.2 again.  Sorry 'bout that.

1.5.3: 
fixed s2_style() to only include the style when loading the Subscriber management page adjusted subscribe.php to (hopefully) utilize the active theme (WordPress 1.5+ only)

1.5.2: 
fixed subscribe.php link generation (thanks Anthony: http://www.anthonyemigration.net/)
added check before including upgrade-functions.php (thanks Indi: http://www.indi.ca/)
added $categories_to_skip to allow bypass of email for certain categories
added email notification to admin on successful (un)subscribe operation

1.5.1: 
fixed problem for 1.2 users

1.5: 
integrated management into WordPress admin section

1.1: 
added is_array() checks to suppress spurious PHP warnings (thanks aalex: www.sourcelibre.com)
fixed broken $form calls (d'oh)

1.0: 
first version