Remove NullHandledAbort property

[pepone]

Now that we are using only std smart pointers we should remove this property

rg NullHandleAbort  
config/PropertyNames.xml
351:        <property name="NullHandleAbort" />

js/src/Ice/PropertyNames.js
132:    new Property("/^Ice\.NullHandleAbort/", false, null),

scripts/IceGridUtil.py
142:            "Ice.NullHandleAbort": 1,

scripts/Util.py
3669:            props["Ice.NullHandleAbort"] = True

java/src/Ice/src/main/java/com/zeroc/IceInternal/PropertyNames.java
129:        new Property("Ice\\.NullHandleAbort", false, null),

csharp/src/Ice/PropertyNames.cs
129:             new Property(@"^Ice\.NullHandleAbort$", false, null),

cpp/src/Ice/Instance.cpp
989:                if(_initData.properties->getPropertyAsInt("Ice.NullHandleAbort") > 0)

cpp/src/Ice/PropertyNames.cpp
126:    IceInternal::Property("Ice.NullHandleAbort", false, 0),

cpp/test/Ice/services/Client.cpp
23:    properties->setProperty("Ice.NullHandleAbort", "0");