Sorry for being a noob, but I have a question about plugin development -
Bit of background - I just built my first (very basic) plugin (super custom for a project I'm in progress on), which didn't include an options menu (because it's so basic) - so I'm a little lost to begin with. I did find the codex on how to add your plugin options to the admin menu - http://codex.wordpress.org/Adding_Administration_Menus - but it didn't really answer this question for me -
I've installed some plugins, as directed, by placing them in the mu-plugins folder. Later, I've found that, for whatever reason, I decided later not to use them (didn't work, didn't need it afterall, etc.), and I've deleted them out of the directory with no issues (they did not come with an uninstall option). However - I've had some issues with "completely uninstalling" some plugins on 2 completely separate Wordpress MU installs now, and it's annoyed me enough to ask.
In my latest adventure, I installed a certain plugin (MUTags) in my mu-plugins folder, and to remove it, I deleted it out of my mu-plugins folder. However - The Mu Tags Admin menu STILL shows up under the Site Admin menu - although the link is broken (because the file it's referencing is no longer on the server, of course).
Why is that plugin's options menu link (broken as it is) still showing up? Are these plugins throwing something into the database, thus the broken-link admin options menu is still there?
And, most importantly - How do I "completely" uninstall plugins that do this?
Most appreciative of any insights anyone can offer.