Clean up todo.org

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
Add `weechat-monitor-buffer-function'.

Function called when a buffer is monitored. Useful for notifications.

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
Add `weechat-sync-active-buffer': Sync current buffer with relay.

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
Send buffer-change (from `weechat-sync-active-buffer') message once.

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>