For version 4.4:
* PowerDNS plugin

For version 4.3:
* unixsock plugin: Remove the custom cache if possible.

src/battery.c: commend not working code.

Wishlist:
* Update the RPM specfile to
  - build `collectd-apache'
  - be free of syntax errors.
* Port nfs module to solaris
* Port tape module to Linux
* Maybe look into porting the serial module
* Build Darwin package
* Maybe let the network plugin configure whether or not notifications should be
  sent/received.
* Maybe find a way for processes connected to the unixsock plugin to receive
  notifications, too.

http://developer.apple.com/documentation/DeviceDrivers/Conceptual/AccessingHardware/AH_IOKitLib_API/chapter_5_section_1.html
http://developer.apple.com/documentation/DeviceDrivers/Conceptual/IOKitFundamentals/index.html#//apple_ref/doc/uid/TP0000011
http://www.gauchosoft.com/Software/X%20Resource%20Graph/
http://johannes.sipsolutions.net/PowerBook/Apple_Motion_Sensor_Specification/