MailPlugin: skeletal implementation.
PetPlugin: do not repeat about-to-die notifications. Close #122
Merge pull request #137 from rexim/issue_122

PetPlugin: do not repeat about-to-die notifications.
DAO: small changes in the API. Add MailDAO. Move core actor references to BasePlugin.
MailPlugin: initial database version and DAO.
MailPlugin: small fixes, enable plugin.
JabberProtocol: improve message send status.
MucMessageHandler: improve participant handling in some weird cases.
MailPlugin: put messages to the queue only when the queue is not full.
MailPlugin: final tuning.
Merge branch 'origin/mail'. Close #43.
README: add mail documentation.
README: fix the mail command name (oh me).
MarkovPlugin: use distinct actors for users from different rooms. Close #60.
Application: take configuration file path from the arguments. Close #146.
Core: add time to all APIs. Declare MessageProcessor method as abstract.
LogPlugin: empty implementation.
Implemented WtfPlugin. Close #92.
Merge pull request #152 from rexim/wtf

Implemented WtfPlugin
WtfPlugin: proper handling of empty entries. Close #155.