FEAT: Generate JNI headers

FEAT: Generate JNI headers during compilation process

Principle: "avoid hardcoding".

Now headers are hardcoded and placed in repository, but they should be generated automatically.

N/A

Bump to Java 10 (javah executable is deprecated since Java 9 and removed in 10, so better is use newer version)
Use plugin to generate headers
Profit

$ cd pmemkv-binding/src/main/java
$ javah io.pmem.pmemkv.Database
$ ls
io  io_pmem_pmemkv_Database_Builder.h  io_pmem_pmemkv_Database.h