add `M-<RET>` for additional binding for `ido-enter-dired`.
Merge remote-tracking branch 'origin/master'
update `accessible-directories` to keep the data order.

- enable `icomplete-mode` by default
- `yas/prompt-functions` uses `yas-ido-prompt` first
minor update for `vim-modeline` and add comments to `init.el`
reorder `hippie-expand-try-functions-list`
optimize loading `snippets/mail.el`

- requiring packages _smtpmail_ and _starttls_ seems unnecessary.
- port forwarding of SMTP due to the restrictive firewall policy.
optimize loading `snippets/vcs.el`

- remove loading _git_ package (no longer used)
add _uinit_ package and update `init.el` accordingly