Changed OSyncMergerFinalizeFunc to fit the plugin function API pattern:
Changed OSyncMergerFinalizeFunc to fit the plugin function API pattern:

 - osync_bool return value (at least a non-void return value)
 - last arugment is OSyncError**



git-svn-id: e31799a7ad59d6ea355ca047c69e0aee8a59fcd3@5793 53f5c7ee-bee3-0310-bbc5-ea0e15fffd5e

luizluca/opensync-luizluca,luizluca/opensync-luizluca