Feature: attach to active clients on setup

[weilbith]

Closes #66

This improves the lazy loading capabilities of this plugin. If the user has enabled auto_attach, during the setup the plugin will attach itself to all already active clients. This is an addition to the already existing auto-command that will attach to new clients. This allows to source/load the plugin any time and it will work right away having the contact to all clients.

I actually intended to use a dedicated function with a proper name to reduce the complexity of the setup function etc. But as this needs to call the "modules" attach function and there is the grouping of "private" and "public" methods. So I didn't know where to put it else. 😕

[SmiteshP]

I actually intended to use a dedicated function with a proper name to reduce the complexity of the setup function etc. But as this needs to call the "modules" attach function and there is the grouping of "private" and "public" methods. So I didn't know where to put it else. 😕

No issues, this is perfectly fine to add in setup function.