Mark skipped test that need a vfunc set up
Make caller-allocate GArray :out arguments work
Object arguments with direction :out are never allocated by the caller
Allocate caller-allocated Structs with .new
Add passing test for GIMarshallingTests.gvalue_in_with_type
Make GObject::Value's #set_value and #ruby_value handle int64
Rename GObject::Value#ruby_value to #get_value
Replace remaining bare skips in GIMarshallingTests

Skips are replaced with explanations or tests.