Improve taskwarrior hooks

[xeruf]

• A separate hook for the start command
• Check if active task is the modified one (multiple tasks may be active in taskwarrior)
• Respect start time

Fixes GothenburgBitFactory/task-timewarrior-hook#13, GothenburgBitFactory/task-timewarrior-hook#16

[lauft]

Thanks for your contribution, please address the comments in the code before this PR can be merged.
And please accept the DCO by signing your commits.

[lauft]

Note to self: Do we really need the :adjust hint here? 🤔

[xeruf]

I think we need a separate hint: The adjust hint bears the problem that changing a start date towards the past might accidentally delete other intervals, at the same time if you have two intervas back to back and you want to move the start time of the latter one back, it should do that without complaining.

Idea:

• rename "adjust" to "override"
• create a new hint called "adjust" that will adjust intervals, but will refuse to delete them in the process
  That seems pretty intuitive to me.

[xeruf]

@lauft

[xeruf]

I'll look into the signing at some point - currently I am happy if I get even the code to a satisfactory level.

[xeruf]

Looking good, I have even written a test script to verify and document expected functionality.

Implementing the alternate adjust hint specification as commented above would make this perfect as far as I have seen :)

[xeruf]

@lauft would appreciate your stance regarding my suggestion :)

[lauft]

Migrated to GothenburgBitFactory/task-timewarrior-hook#11

Please continue any discussion of this PR there.