Deprecated filesystem APIs

[peterflynn]

This extension contains unused references to several Brackets modules which are deprecated as of Brackets Sprint 34 (the next release):

• NativeFileSystem
• FileIndexManager (referenced in both main.js and unittests.js)

As far as I can tell all of these modules are actually entirely unused, so this won't cause any problems in the short term. But the deprecated modules will be removed around the end of this year -- and at that point your extension would no longer be able to load. So I suggest removing these unused references soon.

See this discussion thread for more background on these changes.