fix (file-watcher): Better dotfiles detection

Avoid false positive like `../../`
Refer to BrowserSync/grunt-browser-sync/issues/118

Author: Plou

lib/file-watcher.js

@@ -12,7 +12,7 @@ module.exports.plugin = function (bs) {
     var emitter = bs.emitter;
 
     var defaultWatchOptions = require("immutable").Map({
-        ignored:  /[\/\\]\./
+        ignored:  /^([.][^.\/\\])|([\/\\]+[.][^.])/
     })
     .mergeDeep(
         options.get("watchOptions") || options.get("watchoptions")