Don't use `engine-module.txt` as a possible metadata source for all modules

[keturn]

Terasology/engine/src/main/java/org/terasology/engine/core/module/ModuleManager.java

Lines 81 to 84 in 0d39a3b

	Map<String, ModuleMetadataLoader> mmlm = moduleFactory.getModuleMetadataLoaderMap();
	mmlm.put(TerasologyConstants.MODULE_INFO_FILENAME.toString(), metadataReader);
	mmlm.put("engine-module.txt", metadataReader); // FIXME: this should be *only* for engine-module.
	// FIXME: …or maybe engine-module doesn't need a special filename anymore?

I imagine that engine has this unique engine-module.txt filename because it was loaded from a class.getResource call

Terasology/engine/src/main/java/org/terasology/engine/core/module/ModuleManager.java

Line 128 in 0fa1272

try (Reader reader = new InputStreamReader(getClass().getResourceAsStream("/engine-module.txt"), TerasologyConstants.CHARSET)) {

instead of a filesystem API that opens a file in the root of a specific directory or archive.

So maybe it needed a name to distinguish it from a /module.txt file that might have been put there by anything else on the classpath?

but now that we've moved it to org/terasology/engine/ maybe that's enough of a qualifier that it could just be named module.txt again?

[☝ copied from a comment thread on #4622]

This isn't quite release-critical for a first gestalt-v7 release, but it would definitely be good to get done while we're still on the topic before moving down the roadmap to something else.