fixes CORE-18967 'Taskbar toolbar - Right click > Open folder fails'
by restoring the code-path we removed with the guilty
0.4.15-dev-3847-g /9b716539182864bc077e362febcda74da50287ed
and add test_sei_lpIDList to shell32:ShellExecuteEx apitest test to protect
that functionality on future attempts to simplify.