Murphy hit me in the face

Closes https://github.com/simplesamlphp/simplesamlphp/pull/782

Merge branch 'getMetaDataPdo' of https://github.com/manu0401/simplesamlphp into manu0401-getMetaDataPdo

consentAdmin: Add attributes.exclude option to correspond with the Consent module

Get consentAdmin to send better state information to processStatePassive

Fix #828, infinite loop in AttributeMap behavior

Improve handling of paths containing Windows-style drive letters

(all SimpleSAMLphp source code should be updated, not only this contribution)

Make SHA-256 the default signature algorithm.

SHA-1 is still supported but needs to be configured explicitly if you need it.

smartattributes: fix bug

Per suggestion from @jaimeperez, rename the undocumented
noconsentattributes option to be more consistent with other things and
with what has been done in the ConsentAdmin module. The old version
remains supported for backwards compatibility but issues a warning.

Fixes https://github.com/simplesamlphp/simplesamlphp/issues/841

The Consent module has a (currently undocumented) noconsentattributes
option that allows specified attributes to be removed from the consent
hash calculation. The noconsentattribute option was introduced at
simplesamlphp/simplesamlphp@1efcfa8 but no corresponding option
was added to the consentAdmin module. Thus if people are using the
noconsentattribute option to remove attributes, the consentAdmin module
will *always* show this as attribute values having been changed.

This is a rework of simplesamlphp/simplesamlphp#531 which has gotten corrupted over time.