server: Make create_mapping use struct object_attributes and set the security descriptor of file mapping objects.

server: Make create_mutex use struct object_attributes and set the security descriptor of mutex objects.

server: Make create_semaphore use struct object_attributes and set the security descriptor of semaphore objects.

iphlpapi: For platforms that do not implement /proc, return Unimplemented for the functions trying to read from there.

advapi32: Print out the unknown value for sid use in the LookupAccountName test, instead of the known value.

comctl32: Don't set the focus to the text box when the ComboBoxEx receives a CBN_SELENDCANCEL notification.