Fix ENOENT, EISDIR, EEXIST errors in livesync

During the last refactoring we've lost the queue of futures. So we had some racing issues when the same file is saved multiple times.
Fix this by adding back the queue and adding some try-catch statements.

Also update gaze in order to fix some ENOENT errors.

Author: rosen-vladimirov

lib/common

@@ -39,7 +39,7 @@
     "ffi": "https://github.com/icenium/node-ffi/tarball/v2.0.0.1",
     "fibers": "https://github.com/icenium/node-fibers/tarball/v1.0.6.3",
     "filesize": "3.1.2",
-    "gaze": "0.5.1",
+    "gaze": "0.5.2",
     "gulp": "3.9.0",
     "iconv-lite": "0.4.11",
     "inquirer": "0.9.0",