provide stub for JVM_UnloadLibrary
provide stub for JVM_UnloadLibrary

It may leak file handles under certain circumstances to do nothing in
JVM_UnloadLibrary, but, for now, an empty implementation is more
useful than one that aborts the process.

MaartenR/avian,lostdj/avian,dicej/avian,minor-jason/avian,MaartenR/avian,joshuawarner32/avian,minor-jason/avian,marcinolawski/avian,getlantern/avian,MaartenR/avian,lwahlmeier/avian,lwahlmeier/avian,bgould/avian,getlantern/avian,bigfatbrowncat/avian-pack.avian,dicej/avian,dicej/avian,bigfatbrowncat/avian-pack.avian,ucdseniordesign/avian,lostdj/avian,minor-jason/avian,MaartenR/avian,minor-jason/avian,ucdseniordesign/avian,marcinolawski/avian,getlantern/avian,dicej/avian,marcinolawski/avian,bigfatbrowncat/avian-pack.avian,ucdseniordesign/avian,lwahlmeier/avian,bgould/avian,lwahlmeier/avian,bigfatbrowncat/avian-pack.avian,joshuawarner32/avian,joshuawarner32/avian,lostdj/avian,lostdj/avian,joshuawarner32/avian,bgould/avian,marcinolawski/avian,bgould/avian,getlantern/avian,ucdseniordesign/avian