Execute tracer task using Main.worker.submit()
Move LpisRecord variable into trace() task function
Move RuianRecord variable into trace() task function
Move RuianLandsRecord variable into trace() task function
Create PleaseWaitRunnable object inside tracer modules
Encapsulate LPIS trace code into LpisTraceTask class
Split LPIS tracing to async download and synchronous polygon edits

Also cleanup LpisModule class and tracer code...
Add basic cancellation of LPIS tracer task

Still not perfect, it should break and close the connection
to remote LPIS server.
Encapsulate RUIAN trace code into RuianTraceTask class

Also split the tracer code to async download and synchronous
map updates, cleanup RuianModule class and code.
RUIAN: switch m_finished and m_valid_from
ConnectWays: fix Node is already deleted exception caused by tail
Do not use svn commit no. as Tracer-testing plugin version
Do not use svn commit no. as Tracer-testing plugin version
Cleanup: rename myWay (Node, WayFragment) to masterWay (Node, WayFragment)
Fix Remove spare nodes function
ConnectWays: cleanup
ConnectWays: more cleanup
ConnectWays: use global list of deleted nodes
Fix Duplicated nodes issue in LPIS module

Nodes of Traced way were not inserted in global list of
nodes in the ConnectWays class. So new duplicated node
was created instead of reusing of already existing node.