ActiveQt: Metaobject handling is broken

1) Due to changes to metaobjects, QAxBase::qt_static_metacall has replaced a direct qt_metacall use in ActiveQt. The qt_static_metacall function offsets the method id, which seems to be necessary when slots are invoked via Qt, but breaks when invocation comes via COM interface.
Fix is to correct the offset where necessary.

2) In MetaObjectGenerator::metaObject() function (qaxbase.cpp), the assert Q_ASSERT(!typeName.isEmpty()) is wrong, as empty typename is a valid result here.
Fix is to remove the assert.

3) The type_map in qaxserver.cpp needs "void" -> "void" mapping, as QMetaMethod::typeName() no longer returns empty string for void.