Central mk.sh script

[mcarans]

Versions and build dates all obtained once
Everything passed by parameter not env var
Use bash functions rather than scripts where possible
Targets now named deployment, dev, test and debug (no snapshot etc.)
Updated compiler flags to use the same naming for consistency and clarity
Remove Makefile

Fixes #684
Fixes #671

See usage of mk.sh in README: https://github.com/mcarans/oolite/blob/mk_script/README.md
You can type ./mk.sh help for help on the targets and options

[mcarans]

Builds are here: https://github.com/OoliteProject/oolite/actions/runs/28303563872/attempts/1
(I forgot that release is skipped for PRs and reran the release job unnecessarily)

I've tested on Windows and Linux and looks good to me.

EDIT: builds are here https://github.com/OoliteProject/oolite/actions/runs/28349179837?pr=688

[phkb]

I noticed the "Schemata" folder is not being copied into the Resources folder. Which means the verifyOXP option will have difficulty doing anything. I think this has been the case for a little while now, certainly before this PR. I'm happy to create a separate issue to track the resolution, though.

[mcarans]

@phkb Good you noticed that. Yes please create a separate issue as it's a bug that precedes this PR. Let me know if you see any other problems.

[mcarans]

@phkb @oocube this PR is ready for review