fixes for rpl_log test to make it config-independent


BitKeeper/etc/ignore:
  Added mysql-test/r/rpl_log.eval to the ignore list
client/mysqltest.c:
  support for eval_result and let $var = `query` syntax
mysql-test/Makefile.am:
  import more variables into mysql-test-run
mysql-test/mysql-test-run.sh:
  if we got wrong result on eval_result test case, diff against the
  expanded result, not the template
mysql-test/r/rpl_log.result:
  change config-dependent parts of the result to dynamic variables
mysql-test/t/rpl_log.test:
  get server version from the server
  remove obsoleted replace hack to solve port problem - use eval_result
  instead