define MODULE_VERSION

Task-number: QTBUG-29838
Change-Id: Ia1f68b4ea2ef72c0ba6b2d05a5ed25dca656a63e
put hbtree in a namespace

Change-Id: Ibf9ea22d79b362872075cf219f112bfa5e865b76
don't overload operator<(const QVariant& lhs, const QVariant& rhs)

it introduces ambiguity

Change-Id: I55bf26acbafbb4e582cee19f18237a927b692c4e