Allow overriding task data and taskrc file on the command line

[fdela]

Currently, taskrc file location is overridable in vit config.ini file (and indirectly via TASKRC envvar)

[taskwarrior]

# Full path to the Taskwarrior configuration file. Tilde will be expanded to the user's home directory.
# NOTE: This setting is overridden by the TASKRC environment variable.
#taskrc = ~/.taskrc

TaskWarrior gives two ways to override config file and data location, via command-line or environment:

	Config file	Data location
Command-line argument	rc:config_file	rc.data.location:data_directory
Environment variable	TASKRC=config_file	TASKDATA=data_directory

See CONFIGURATION FILE AND OVERRIDE OPTIONS section in task(1) manpage for details.

Overriding manually the environment via TASKRC and TASKDATA (used by TaskWarrior) before launching vit works currently, and shown data/used config are correct.

What would be useful it to be able to specify those via vit command line, as task does:

task rc.data.location:alternateDataLocationDirectory rc:alternateTaskrcConfFile ...

This would allow for instance to have completely separate environments, without having to rely on contexts (where it's a soft separation).

Linked issues: #257 and #235

[thehunmonkgroup]

See #257 for the suggestion there, perhaps a single --default-args switch?

[fdela]

See #257 for the suggestion there, perhaps a single --default-args switch?

Yes, a --default-args would do, to pass to every taskwarrior command.
Care should be taken to respect precedence of options, so they are applied by increasing precedence: config.ini -> environment variable -> command line option

E.g. taskrc option in config.ini -> TASKRC -> --default-args rc:...

[thehunmonkgroup]

I've abandoned the idea of a --default-args approach, too complicated.

I've also abandoned the idea of any VIT-specific overrides for task data, see #257 (comment) for more.

I'd still consider adding a CLI arg that would allow overriding the task data location -- this is reasonably straightforward, compliments the existing config file option, and allows for more flexibility for those using more complex setups.