Database instances not reclaimable by GC

[mmimica]

Two linked issues:
NativeDatabase ctor is not invoked when an instances is created by hs_compile_multi, so deallocator is not registered there.

In com.gliwka.hyperscan.wrapper.Database#load(java.io.InputStream, java.io.InputStream), the ctor is called, but the deallocator lambda contains a reference to ṫhis, which makes it non-reclaimable by GC.
this.deallocator(() -> hs_free_database(this));

[simpleyetawesomeprojects]

hello @mmimica , I have a question unrelated to your PR. I'm stuck on a problem and could not solve it. I guess you might have an idea, I have created an issue here gliwka/hyperscan-java-native#29. I would highly appreciate it if you can provide any suggestions on how the issue could be resolved. Thank you in advance and apologies for this unrelated comment.

[mmimica]

Sorry, I'm not up to the task. All I know about javacpp I have learned by looking at your code.