unsafe mode

Introduces unsafe mode:

• adds cli argument --insecure-plugin-script my_plugin_name=/path/to/my/script
• when running a plugin, matches passed container with the part before the "="
• if it matches, set standard environment variables & executes the files defined in the part after the "="

@vasili, please review and let me know what I need to update in order to get this to dev branch quality. This has been manually tested on my local machine with both docker plugins and insecure plugins. Both worked correctly