Ido-style backspace in find files

I really miss the ido-style backspace when finding files.  I think it would be logical to use this whenever you are auto-updating.  That way a backspace may not be a moot point.
Helm M-[ issue

This plagued ergoemacs-mode for a long time... But I fixed it :)

See Issue #321.

You may want to be careful of M-[ M-O and ESC in the future as well. Emacs suggests you don't bind these keys at all:

http://www.gnu.org/software/emacs/manual/html_node/elisp/Translation-Keymaps.html

```
... it is better to avoid binding commands to key sequences where the end of the key sequence is a prefix of a key translation. The main such problematic suffixes/prefixes are <ESC>, M-O (which is really <ESC> O) and M-[ (which is really <ESC> [).
```
Made this only apply when the current key is M-[

This way if someone decides to rebind M-[ to something else, you don't have to try to work around the M-[ issue.
Fix stray f
Expand user name directories like ~root/ (just like ido-find-file)

I also miss expanding named directories like ~root/.  Ido currently does this.
Merge pull request #329 from mlf176f2/patch-3

Expand user name directories like ~root/ (just like ido-find-file)
Merge pull request #328 from mlf176f2/patch-2

Helm M-[ issue
Merge pull request #327 from mlf176f2/patch-1

Ido-style backspace in find files