file-indexer is not discriminatory enough

[zgohr]

Example: I can't start feather while I'm editing a file in /rest because VIM creates a swap .swp file that the file-indexer picks up and throws an error on. I would submit a pull request but I'm not sure the best way to handle the situation in with preference to staying generic.

[ryedin]

nice find... will definitely have to address that somehow