On the invoke-diff-cmd branch:  Add guard against concurrent usage of
incompatible diff options.  Remove previous guard code.

* subversion/svn/svn.c

  (sub_main): Add guard against concurrent usage of incompatible diff 
    options.  Remove previous guard code. 




git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/invoke-diff-cmd-feature@1488657 13f79535-47bb-0310-9956-ffa450edef68