Plugin in subfolder for github? Is it possible to have Craft plugins in subfolders of craft/plugin/ instead of having them right in that folder?

So that I can have a parent directory that is my git repository craft/plugin/mypluginrepo/ containing a README.md and other files and folders besides the actual plugin craft/plugin/mypluginrepo/myplugin/.

I know you can change the plugins path via the PHP Constant:
define('CRAFT_PLUGINS_PATH', '../craft/plugins/subfolder/');

unfortunately this only allows me to set one folder.
I don't think it's currently possible.  There are several places where we're explicitly checking for the plugin's handle as a folder directly underneath whatever craft()->path->getPluginsPath() is returning.