Fixes PHP 5.2 errors on activation

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2314 f69abe3c-2ee2-4550-9a6d-17bd458115be
switched manual check to a trigger for do_action and disabled wp-mail.php entirely

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2315 f69abe3c-2ee2-4550-9a6d-17bd458115be
fixed a bug that was resetting checkbox options to default on check_mail

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2316 f69abe3c-2ee2-4550-9a6d-17bd458115be
Upgraded to horde_imap_client-2.15.2

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2317 f69abe3c-2ee2-4550-9a6d-17bd458115be
Reverted Socket.php, Socket/Pop3.php and Base.php to d5ac35d (before continuations were introduced)

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2318 f69abe3c-2ee2-4550-9a6d-17bd458115be
various shenanigans to fix up PHP 5.2 support

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2319 f69abe3c-2ee2-4550-9a6d-17bd458115be
fixed option validation and detection of unconfigured/error states

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2320 f69abe3c-2ee2-4550-9a6d-17bd458115be
get rid of 'slow down, cowboy' and delete transient after an error

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2321 f69abe3c-2ee2-4550-9a6d-17bd458115be
save original sender in post_meta in case we want it later

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2322 f69abe3c-2ee2-4550-9a6d-17bd458115be
added support for attachments

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2323 f69abe3c-2ee2-4550-9a6d-17bd458115be
add shortcode to support custom taxonomy terms

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2324 f69abe3c-2ee2-4550-9a6d-17bd458115be
allow user to configure what to do when sender doesn't match any users (discard or pending)

git-svn-id: http://gsoc.svn.wordpress.org/2013/codebykat/post-by-email/trunk@2325 f69abe3c-2ee2-4550-9a6d-17bd458115be