Alternative TYPO3 composer installers

This is a derivative of the official TYPO3 composer installers at https://github.com/TYPO3/CmsComposerInstallers

I prefer to differentiate strictly between 'automatically installed sources' (by composer, that go into the vendor directory and can be automatically overwritten again) and 'manually mangled sources' (by me, editable, outside of the vendor directory).

My alternative installer mode installs TYPO3 core and extensions in the vendor directory, symlinking the latter into typo3/ext. As it is absolutely necessary, a single symlink typo3_src is written in the web root directory.

== Configuration Options

Extra option	Description
typo3_vendor_based	(boolean) whether to use my alternative mode
typo3_web_dir	(string) web root directory, defaults to composer project directory.

A composer.json might look like:

{
        "repositories": [
                {
                        "type": "composer",
                        "url": "http://composer.typo3.org/"
                },
                {
                        "type": "vcs",
                        "url":  "http://github.com/KampfCaspar/CmsComposerInstallers.git"
                }
        ],

        "require": {
                "typo3/cms-composer-installers": "1.1.x-dev",
                "typo3/cms": "~6.2",
                "typo3-ter/news": "*",
                "typo3-ter/html5videoplayer": "*",
                "typo3-ter/cooluri": "*",
                "typo3-ter/ke-search": "*",
                "typo3-ter/powermail": "*",
                "typo3-ter/sr-freecap": "*"

        },

        "extra": {
                "typo3_web_dir": "html",
                "typo3_vendor_based": true
        }

}

The explicit mentioning of cms-composer-installers should protect against hidden errors if the original gets updated beyond the point of this derivative.