PATCH: Several apitests for SetupDiInstallClassExA

This patch adds several new tests for SetupDiInstallClassExA.
Basically it proves that SetupDiInstallClassExA shouldn't fail if there isn't a Current32Install.Nt.Service section in the INF file.

Our current API fails* if there is none:

/* Install .Services section */
lstrcatW(SectionName, DotServices);
ret = SetupInstallServicesFromInfSectionExW( hInf, SectionName, 0, hDeviceInfo, NULL, NULL, NULL);
if (!ret)
goto cleanup;

*Actually it doesn't fail due a bug in SetupInstallServicesFromInfSectionExW,which returns true even if the SectionName doesn't exist at all. Fixing that bug, this bug is revealed.