Implement scheduled issues

[billp]

The user should be able to register one or more issues he wants to log every day (like stand up meeting)

The tool will provide the following commands in order to add or remove repeatable issues.

jira-logwork scheduled add XYZ-123 --repeat=[REPEAT] --date=[DATE] --start=[START-TIME] --duration=[DURATION] 
jira-logwork scheduled remove XYZ-123
jira-logwork scheduled list

[REPEAT]: An integer that indicates the day of the week that this issue will be repeated.

0: Every day
1: Monday
2: Tuesday
3: Wednesday
4: Thursday
5: Friday
6: Saturday
7: Sunday

[DATE]: The date that the issue will be scheduled in MM/DD/YYYY format.
[START TIME]: Time in 24h format, e.g. 10:00
[DURATION]: String representation of duration, e.g. 30m, 1h30m, etc.

@sotcha what do you think?