Silence a few more integer width warnings by manually casting values to comply with external APIs.
Silence a few more integer width warnings by manually casting values to
comply with external APIs.

* subversion/libsvn_ra_svn/cyrus_auth.c
  (try_auth, sasl_read_cb, sasl_write_cb, svn_ra_svn__enable_sasl_encryption):
    Cast arguments to unsigned int's, as required by the SASL APIs.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion