Make `status` target always shows outdated

[cassava]

I realize that make status says that it's approximate, because it compares the package age with all the files in the package directory, but this is causing confusion for our users.

There are several issues at play here though regarding ok vs outdated:

1. make status may not represent the package you're interested in, since there might be one linked to boost/1.68 that is ancient but another that is linked to boost/1.78.0 that is up-to-date. How are we even to know which configuration the user is interested in?
2. make status may not be accurate, since we modified a file that is not contributing to the package (eg. README), making it look as though the package is outdated, when it is not.

Really, the whole point of make status is the following:

A. Ensure that I don't forget to export changes to recipe or sources. B. Ensure that I don't forget to build a package if it's outdated. C. Tell me if this package is in editable mode or not.

It would be easy enough to solve problems (1) and (2) with cloe-launch. However, cloe-launch cannot by nature address (A) and addressing (C) doesn't make much sense for cloe-launch.

---

Proposed solution:

• Use ok? and outdated? in output from make status
• Add check to cloe-launch to check if package is out-of-date (how?)
• Print warning in cloe-launch when a user is using out-of-date packages
• Fix Python stack-trace when a package does not exist

This last point would fix the unreadable output from cloe-launch when the requirements are not available.

[cassava]

Case in point:

make package-auto followed by make status:

$ make status
ok       : fable/0.19.0-nightly@cloe/develop
outdated : cloe-runtime/0.19.0-nightly@cloe/develop
outdated : cloe-models/0.19.0-nightly@cloe/develop
outdated : cloe-oak/0.19.0-nightly@cloe/develop
ok       : cloe-engine/0.19.0-nightly@cloe/develop
outdated : cloe-plugin-gndtruth-extractor/0.19.0-nightly@cloe/develop
outdated : cloe-plugin-basic/0.19.0-nightly@cloe/develop
outdated : cloe-plugin-speedometer/0.19.0-nightly@cloe/develop
outdated : cloe-plugin-virtue/0.19.0-nightly@cloe/develop
outdated : cloe-plugin-mocks/0.19.0-nightly@cloe/develop
outdated : cloe-plugin-noisy-sensor/0.19.0-nightly@cloe/develop
outdated : cloe-plugin-minimator/0.19.0-nightly@cloe/develop

The fable and cloe-engine are only showing ok because I ran make -C fable package and make -C engine package.

[cassava]

One thing which would solve (A) is the use of lockfiles with make status. This would involve creating a lockfile for each package right now though... which would increase the time to run for make status significantly.

[cassava]

The commit referenced above solves (1) by adding LOCKFILE_SOURCE support to status. This makes it orthogonal with all the other targets.