SVGHMI: do not discard out-of-page elements inside widgets that are ovelapping pages.

SVGHMI: update generated XSLT

OPCUA: cosmetic fixes

CLI: poll runtime log and output new entries to stdout.

CLI: when using --keep, do not disconnect before being interrupted

Runtime: work around 1s delay added when using twisted reactor's callLater.

Since wxPython4, using wxReactor from non-main thread was producing
exceptions in wxWidget's C++ code. Then reactor.run() was called from
main thread, and runtime's worker was delegating calls to reactor
with callLater(0, callable).

While this worked perfectly with wxReactor, it did introduce an unexplained
1 second delay to each worker call when using nomal linux reactors
(i.e. without wxPython). As a workaround reactor runs in a thread when using
twisted without wxPython

tests: opcua_client test project is not meant to be encrypted.

SVGHMI: update generated XSLT files

Merged changes from default

SVGHMI: ensures that PLC sends only fresh data to HMI, even right after variable being subscribed.

OPC-UA: add logging to help user to understang what went wrong when connecting.

OPC-UA: fix LDFLAG, missing OpenSSL's -lcrypto

open62541 is linked staticaly, therefore shared object dependencies have to be given explicitely.

tests: missing SSL support in open62541 build parameters

Merge changes from default branch

merge