Add more tests for SimpleSAML_Configuration::getDefaultEndpoint() and SimpleSAML\Utils\Config\Metadata::getDefaultEndpoint().

Make it possible to pre-load a configuration array into SimpleSAML_Configuration for subsequent calls to getInstance() to use it. This opens up for unit-testing code that calls SimpleSAML_Configuration::getInstance().

(being respectful with occurences that might change the behaviour, i.e. default database prefixes)

Refactor SimpleSAML\Utils\Arrays::normalizeAttributesArray() to SimpleSAML\Utils\Attributes::normalizeAttributesArray().

Refactor SimpleSAML_Auth_State::extractPersistentAuthState() to getPersistentAuthData() to avoid confusions around the behaviour of this method.

Move SimpleSAML_Auth_Default::extractPersistentAuthState() to SimpleSAML_Auth_State::extractPersistentAuthState() and deprecate the former.

Move the DatabaseTest to tests/lib/SimpleSAML/ where it belongs. Reformat code. Fix a few issues with phpdoc. Removed some unused variable. Use typed methos from SimpleSAML_Configuration instead of getValue().

Reimplement \SimpleSAML\Utils\Crypto::aesDecrypt() and \SimpleSAML\Utils\Crypto::aesEncrypt() to use openssl instead of mcrypt. This removes the direct dependency on mcrypt and closes #228.

Move the aes[En|De]crypt() functionality in \SimpleSAML\Utils\Crypto to internal methods where the secret is passed as a parameter. Then we don't need a working configuration to test the functionality.

This reverts commit aec9571d.

Add tests for most of the data retrieval functions. No tests
for the metadata functions present though.

* One test suite for all tests.
* One file per class that is tested.

These changes should make it easier to add new tests.