Vim: Add bundle 'CtrlP-Z' (with extra settings)

CtrlP-Z is a CtrlP interface of fasd (Z).

- Polish ctrlp's custom ignore settings
- Map ',z' to CtrlP-Z

- NerdTree's ChDirMode is set to 1, so that the CWD
  is automatically changed to the directory hitted by CtrlP-Z