Let gs handle commits the branch is behind

Fixes #119
Merge pull request #120 from sblask/fix-issue-119-show-more-information-in-gs

Let gs handle commits the branch is behind
Fix upcoming Git 2.0 breaking change to `git add -A`.
Ensure C locale is used when processing command output

This change makes sure LC_MESSAGES is set to C whenever command output
is run through grep, sed etc. Otherwise aliasing will fail whenever
localized messages are printed.

This should fix #98 and #64.
Merge pull request #137 from ilkka/master

Ensure C locale is used when processing command output
Merge pull request #131 from chasballew/git_add_all_deprecation_fix

Fix upcoming Git 2.0 breaking change to `git add -A`.
Changing the output for git status when there is a rename and modify at the same time
make _create_or_patch_scmbrc noclobber safe

use >| instead of > to override noclobber on write (works for both bash and zsh)
Merge pull request #147 from keen99/patch-1

_create_or_patch_scmbrc is not noclobber safe
add a bit more detail around install.sh in readme

install.sh is really required, you can't just clone source and go.
Merge pull request #148 from keen99/patch-2

add a bit more detail around install.sh in readme
Merge pull request #145 from aero-z/fix-rename-modify

Don't show oldname -> newname for unstaged modifications
`gh` is the new `hub`

`gh` is the new `hub`, rewritten to be fast and efficient.
http://owenou.com/gh/

If has been adopted by GitHub themselves and will replace `hub`
entirely, see:
https://github.com/github/hub/issues/475

This patch simply checks for `gh` as a possible `_git_cmd` in addition
to hub, restoring scm_breeze functionality for people who have switched
to gh.
Merge pull request #150 from mroth/gh

`gh` is the new `hub`
fix ability to undefine default aliases in zsh

The ability to not define default aliases in the `.git.scmbrc` file
leading to not having those aliases not present worked fine in bash.

However, this seems to still have thrown an error in zsh.  For example,
if you commented out the line:

        git_checkout_alias="gco"

then when sourcing scm_breeze aliases.sh would throw an error.

This applied only to aliases defined with the `_alias()` function and
not those with the `_git_alias()` function.

To fix this, I wrapped `_alias()` in a similar check to the one
`_git_alias()` has, where it passes the portions as arguments and
verifies the first is present before proceeding.

I'm not 100% certain why seperate functions exist for these two things
to begin with (as far as I can tell from a cursory examination the main
difference is `_git_aliases()` defines a tab completion?) but I believe
my change has fixed the ability to comment out aliases in `.git.scmbrc`
in zsh for users who do not want them (I'm in this boat, there are too
many for me and I get confused).

I tested manually in both bash and zsh and it appears to work, however
you might want to review this before merging given my relative
unfamiliarity with the codebase.
aliases: consistent indentation and quotation

this is unrelated to the previous commit and zero functionality but
while I was changing things I wanted to clean up the indentation and
use consistent single quotes versus double quotes in the functions
calls for `_alias()` and `_git_alias()`.

In my opinion this makes the file more readable, but if it bothers you
let me know and I’ll be happy to remove it from the pull request.
Merge pull request #151 from mroth/zsh_undefine_alias_fix

fix ability to undefine default aliases in zsh