Implement lokconf_init.

This is a simple executable which can be used to ensure there is a
pe-pared configuration for unit-tests to avoid the usually required
re-start on the first run.

Change-Id: I49b706e8daa93bc34db508a24615b63b9babddba
Add gb_CppunitTest_use_confpreinit:

For unit tests that use the VCL event loop we can use this to
avoid the otherwise required restart.

Change-Id: I48265d7e7188a4efaa6f87432c762320331c0c78
Use gb_CppunitTest_use_confpreinit for LOK tiled rendering.

Now that we use the event loop for LOK we need to make sure that
it is able to run successfully first time, as unit tests start
with a completely clean config.

Change-Id: If9ddcb75fe8286381d71ecdc76ac7eb3697960d0
gtktiledviewer: make sure we clean up the office instance.

Change-Id: I12c3e9df8b8fcf8dcd6fb5fa781c2f7c10ab0a0c
DON'T USE: ignore unknown args instead of failure.

The --protector flag ends up here in unit tests, which causes things
to fail -- either we need to make --protector known, or filter
it out before hand -- whereby I suspect filtering it out would be
difficult to do in a reliable fashion.

Change-Id: Iab47a6e24723604df75def2b963e82ba6479318e