Various class Git improvements

[bobbingwide]

For oik-shortcodes to work against Git repositories we need to add logic to class Git to do the following

• Find the current SHA using git log --oneline -1
• Check if the folder is the root of a git repo, using 'git rev-parse --show--cdup`

We also want to be able to check all the Git repos to find outstanding changes that need to be checked in. So we'll add a new method check_status and simple routine to run it.

[bobbingwide]

The simple routine to invoke Git::check_status() is a new file called oik-git.php You invoke this using batch from the directory above the Git repos e.g. use this to check the Git plugins

cd wp-content\plugins
batch oik-batch\oik-git.php

where batch.bat is, in my development environment

php c:\apache\htdocs\wordpress\wp-content\plugins\oik-batch\oik-batch.php %*

This causes oik-batch.php to run a subset of WordPress that invokes the oik-git.php routine ensuring the pre-req APIs are available.