Server should issue delete before update commands.

Currently when you update from cvs it seems that it will try and add files
first before removing files that have been deleted from cvs.  It is
important to delete first in order to avoid the case where someone has
renamed the case of their file, in effect deleting the old file and creating
a new one of the same name but different case.  When this case occurs
eclipse and wincvs window clients trys to add the file of the same name -
with different case - first and fails since a resource already exists with
that name.  If the cvs server had send the "delete file" command first then
no error would occur.