Revert "Removes PHPExcel in favor of composer managed one"

This reverts commit 5cadb8424877288af0ee3668cd5a37cbf07de475.
Uses composer not for managing PHPExcel any more
The composer autoloader implementation makes it really hard to run the library tests also in applications that embed the Arcavias core
Merge pull request #228 from nsendetzky/master

Uses composer not for managing PHPExcel any more
Adds composer and MShop autoloader so we are not dependent on Zend_Loader
Merge pull request #229 from nsendetzky/master

Adds composer and MShop autoloader so we are not dependent on Zend_Loader
Fixes fatal error when quick search was used
Merge pull request #230 from nsendetzky/master

Fixes fatal error when quick search was used
Removes replacing the version in the manifest file as it isn't used any more
Makes available sites configurable
Merge pull request #231 from nsendetzky/master

Makes available sites configurable, removes replacing the version in the manifest file
Extends catalog manager to return nodes, path or tree from the deepest site to the top level site if available
Merge pull request #232 from nsendetzky/master

Extends catalog manager to return nodes, path or the tree from the deepest site to the top level site if available