[cutes] extension libraries are handled by separate entity

And QLibrary is shared between different environments and unloaded
only if not used by any.

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[cutes] cutes.gc() method

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
tracing

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[tests] correct paths for qml import etc.

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[actor] more reliable actor hold locks management

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
take into account prefix can be empty

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[cutes] -V/--version to show version

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[cutes] CppOwnership should be always claimed after newQObject()

newQObject() sets ownership to JavaScriptOwnership

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[lib] return js array as the result of convert()

QObjects passed in QList<QObject*> or QVariantList are collected as
garbage for some reason...

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>