* Fix inaccurate class comment that was copied from an unrelated
module in MediaWiki core.
* Remove use of deprecated getModifiedTime(). While this implementation was
straight forward, it is more reliable and deterministic to use a content hash
because timestamps are not tracked by Git. This currently causes needless
cache invalidation for all users at Wikimedia every week because git-clone
starts with fresh timestamps on disk.
I'm not using enableModuleContentVersion() right now because calling
getScript() reads all files into memory which is more expensive than
simply hashing the files. Especially because safeFileHash() is backed
by an APC cache via FileContentsHasher.
This matches the implementation in core ResourceLoaderFileModule.
Change-Id: If9aaefa6a3cf047c6c36e1cdd0f350412d59c849
2ab168f113