ensure Object.notify is available for Android classpath build and reduce duplication
cp/avian/java-net.cpp: fix segfault

In Java_java_net_InetAddress_ipv4AddressForName:
  Throw nullptrex on hostname = null.
Merge pull request #354 from dicej/notify

ensure Object.notify is available for Android classpath build and reduce...
Merge pull request #355 from lostdj/patch-1

cp/avian/java-net.cpp: fix segfault
Added missing cp/avian/Math.atan2(double,double)

It was implemented as native function, but wasn't added to java.lang.Math.
Fixed small bug in getClassType() function.
Added some tests for class types
Merge pull request #358 from bigfatbrowncat/avian-pack

Tiny fix in Class.getClassType()
Merge pull request #357 from lostdj/patch-2

Added missing cp/avian/Math.atan2(double,double)