Revert "All the hooks instroduced in 2.1 don't pass variables by ref any more, while hooks already present in 2.0 will still pass by-ref [Issue #54]"

This reverts commit 99797a97d2b5493a802e8dbc1b5e834bb91929ed.

Conflicts:

	Sources/Load.php
	Sources/ManageLanguages.php
	Sources/ManageSearch.php
Some other tweaks to the hooks

Signed-off-by: emanuele <emanuele45@gmail.com>