Move composer location to install libraries into our libraries folder

Now the only slightly irritating thing about this method is that we are merging the framework and /joomla code together in the libraries/joomla directory.

However I think this is so so so much better keeping our Joomla /libraries convention than having stuff split between libraries and composer.

Note any file changes are just a result of running composer update on my host + the necessary change in libraries for the autoloader include + build file paths to files to ignore