The Debian build farm has a number of older and slower machines
which need to run the xrdp test suite.
On these platforms, we occasionally get timeouts where machine load is
high. This results in duplicate issues being raised. It is not obvious
that the issues are duplicates, which wastes time all round.
This commit splits up some test cases into multiple cases and
adds larger timeouts for those cases that are CPU-intensive.
db04b4b54c