* [jvm-packages] Ensure the native library is loaded once
Previously any class using XGBoostJNI queried NativeLibLoader to make
sure the native library is loaded. This commit moves the initXGBoost
call to XGBoostJNI, effectively delegating the initialization to the class
loader.
Note also, that now XGBoostJNI would NOT suppress an IOException if it
occured in initXGBoost.
* [jvm-packages] Fused JNIErrorHandle with XGBoostJNI
There was no reason for having a separate class.
91e778c6db