Add --config-option support to svnsync to allow overriding the default http library by passing --config-option servers:global:http-library=serf.
Add --config-option support to svnsync to allow overriding the default
http library by passing --config-option servers:global:http-library=serf.

* subversion/svnsync/main.c
  (includes): Include private/svn_cmdline_private.h.
  (svnsync__opt): Give enum a name and add svnsync_opt_config_options value.
  (SVNSYNC_OPTS_DEFAULT): Add svnsync_opt_config_options.
  (svnsync_options): config-option.
  (main): Parse and apply config options.

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