FEATURE: level sanity

[shahn]

Levels are currently searched in the working directory. As this is practical for development, we need something else in the long run.

[shahn (shahn)]

We can save levels in "$HOME/.nikki/levels".
(and something equivalent on non-Unix platforms, let "getAppUserDataDirectory" decide.)

If you create a new level, it will be placed there, too.

This will also mean we have a flat list of levels, that have to have unique names. This way, we can't have level packs.

[shahn (shahn)]

A related issue:
Q: Where do we put template levels for the creation of new levels?
A: In data/template_levels!

Not so related after all. We want to install template levels and don't want users to change them. So we handle them just like other data.

[shahn (shahn)]

We may want to have different user data directories for free levels and bought episodes (to keep levels under different licenses apart). Maybe "nikki-community" and "nikki-joyridelabs". Both with READMEs that state if copying is ok or not.

[shahn (shahn)]

The game looks up user data directories where levels should be. We should be able to overwrite these directories for development. Either with environment variables, or with configuration options. (Environment variables seem more appropriate, like $nikki_datadir in src/linuxRunInPlace.sh)

[shahn (shahn)]

The game looks in ~/.nikki-free-levels for community levels now.