Make dry run configurable using launchconfig

[eed3si9n]

migrating from #34

steps

1. cs foo where calling foo --version does something undesirable (like waiting for user input forever).

problem

the installation process calls foo --version and does that thing.

expectations

I would like to propose 2-tier solution to this using launchconfig file. Both of them involve adding an optional section conscript to launchconfig as follows:

[conscript]
  dry-run: false
  dry-run-param: --something-not-version

opt-out

The proposal is that we keep the existing behavior (run script with --version) by default, so existing happy conscript authors don't get sniped from the back. In other words, the new [conscript] section is totally optional.

If the conscript author just doesn't want to use dry-run option at all, they can opt-out by writing:

  dry-run: false

Upon installation we don't do dry-run, and instead we print some warning saying that the jar's still not downloaded.

--help instead of --version

Another scenario is that application does not support --version, but has some other harmless option already like --help.

  dry-run-param: --something-not-version

This let's them customize to whatever. Again, if it's not specified --version is used.

[softprops]

re: "cs foo where calling foo --version does something undesirable (like waiting for user input forever)"
lol, I totally just ran into that, though it was a bug in my conscript. Conscript's opt in main call triggered this call where at first I wasn't checking std in's available method so cs softprops/spakle was literally leaving me hanging waiting for input, just like you said. An override would be nice for this.