Time tracking

This would be an excellent addition to the service.

Ability to log spent time to an issue, or just spent time in general, like time designing or researching etc... for a date.

Maybe ability to add time to an issue via push? i.e.

• Fixes BCLOUD-12, time BCLOUD-1h blablabla; //fixes issue BCLOUD-12 and add 1 hour to it
  or
• BCLOUD-12, time BCLOUD-25m blablabla; //just add a comment to issue 12 and add 25minutes to it's spent time;