Import All should load the config file before anything else #806

Similar to #697 which applies to pull event handlers. Import All should load embedded-git-config.json first to avoid issues where the mapping configuration has changed.

If a config file has never been loaded before such as after having just installed Embedded Git then it should be possible to do a single Import All where it imports the config file first and then proceeds to import everything else. Currently this is only possible with multiple invocations of Import All which is inconvenient.