Squashed 'files/external/vivid-planet-munin-php-apc/' changes from b5aa024..9e18ac3

9e18ac3 support named copies of the plugin, take 2

git-subtree-dir: files/external/vivid-planet-munin-php-apc
git-subtree-split: 9e18ac3b757ce1429d6ed8be43e73a5d7f7f6c0b
Merge commit '68ac09c947a99507e8e8bd9b86f60aa563c8505a'