Git: update .git-*.sh scripts from Git 1.8.2.1

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Zsh: set up Git completion the recommended way

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Zsh: show full path to current working directory in RPROMPT

Zsh will hide it if necessary to make room. This enables us to have a
little more info about where we are without cluttering the base prompt.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Zsh: improve SPROMPT

Replace the standard:

  zsh: correct 'lss' to 'less' [nyae]?

with:

  zsh: correct 'lss' to 'less' [yes, no, edit, abort]?

where the faulty input and the proposed correction appear in red, and
the first letter of each of "yes" ,"no", "edit" and "abort" is bolded
and underlined.

Note that I changed the ordering in the default prompt from nyae to
ynea, to better match the frequency with which I typically select from
among those options.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Zsh: put Git info into RPROMPT

I've always valued a terse PROMPT, and preferably a one-line one, so I
don't really want to go for something lengthy, elaborate, or even
something spread over two or more lines as seems to be all the rage
nowadays.

Using vcs_info and RPROMPT enables me to jam a fair bit of useful info
off on the right without it getting in the way.

I've included a link to the documentation in a comment as it can be had
to find.

This replaces the old .git-prompt.sh script.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Zsh: show Git untracked status in RPROMPT

This commit adds the display of untracked files to the RPROMPT,
piggy-backing off the display of unstaged files.

The order and color of the elements in the status correspond with those
in the `git status` output; ie. staged (yellow), unstaged (red), and
untracked (blue).

Signed-off-by: Wincent Colaiuta <win@wincent.com>