Support recurring tasks

[GoogleCodeExporter]

trafficstars

Tasks which happen every day, week, month, etc. 

Original issue reported on code.google.com by dbarashev on 23 Aug 2011 at 4:06

[ngm]

To help others, noting that #1225 has a couple of suggestions for current 'workarounds', as well as a mockup of how this could be implemented.

[derphizzl]

Any plans to support this feature would be really appreciated!