Automatically add or note plugins that are softdepends

[aakatz3]

Is your feature request related to a problem? Please describe.
It can be confusing of frustrating if a section of StickyAPI uses a particular Bukkit plugin, but doesn't add it automatically to the plugin.yml

Describe the solution you'd like
It would be nice to somehow have StickyAPI interact with Spigradle or however we choose to work with Plugin.yml, to automatically add softdepend plugins

Additional context
Example: Textures in stickyapi has a softdepend on HeadsDB plugin; it would be nice if this could be done automatically