SysInfo related improvements from common

Author: teobugslayer

lib/definitions/osenv.d.ts

@@ -56,7 +56,6 @@
     "shelljs": "0.3.0",
     "tabtab": "https://github.com/Icenium/node-tabtab/tarball/master",
     "temp": "0.8.1",
-    "unzip": "0.1.11",
     "winreg": "0.0.12",
     "xcode": "https://github.com/NativeScript/node-xcode/archive/NativeScript-0.9.tar.gz",
     "xmlhttprequest": "https://github.com/telerik/node-XMLHttpRequest/tarball/master",