Fix call-time pass-by-reference

To support PHP >= 5.4, call-time pass-by-reference must be avoided.
See http://fr2.php.net/manual/en/language.references.pass.php
Merge pull request #86 from thijskh/master

Update links to SSP homepage to point to simplesamlphp.org.
Merge pull request #87 from julienmalik/patch-1

Fix call-time pass-by-reference
Make the search.{username | password} and priv.{username | password} LDAP options available in the authX509 module. Fix #79.
Update the documentation for the sqlauth module, discouraging plain text passwords and adding the appropriate security considerations.
Reformat basic configuration files.
Mark the old SP interfaces in www/ as deprecated.
Mark the old examples in www/example-simple/ as deprecated.
Mark all the files in www/auth/ as deprecated.
Mark the SimpleSAML_Auth_BWC class as deprecated.
Update PHP version required in frontpage_config.php.
Mark as deprecated in SimpleSAML_Session: DATA_TIMEOUT_LOGOUT, $authority, getAuthority(), getAuthnRequest(), setAuthnRequest(), setIdP(), getIdP(), setSessionIndex(), getSessionIndex(), setNameID(), getNameID(), setSessionDuration(), remainingTime(), isAuthenticated(), getAuthnInstant(), getAttributes(), getAttribute(), setAttributes(), getSize(), expiraDataLogout(), setLogoutState(), getLogoutState().
Rename SimpleSAML_Session::getInstance() to SimpleSAML_Session::getSessionFromRequest(), and leave the former as deprecated.
Mark as deprecated in SimpleSAML_Utilities: validateXML(), validateXMLDocument(), validateCABuiltIn(), validateCAExec(), validateCA().
Replace legacy URL with more current version.
Drop obsolete SVN $Id$ keywords.
Update docs to point to actual current download location.
Remove stray </div> that messed up the footer of sanitycheck
aggregator: construct an EntityDescriptor out of the DOMElement before adding it to children.

The aggregator module tries to put a DOMElement into the children attribute of
$entitiesDescriptor, which expects an EntityDescriptor object there. Solves a
PHP Fatal error: Call to undefined method DOMElement::toXML() when invoking
the module.