Added missing property: Assertion encryptionKey
Removed dead code
Fix for issue 578:	[SAML2 Static Analysis] Assertion->decryptAttributes will leave NameFormat to Unspecified
https://code.google.com/p/simplesamlphp/issues/detail?id=578
Initialize variable before use.
Fix for Issue 579:	[SAML2 Static Analysis] AuthnAuthorityDescriptor faulty initialisation of AssertionIDRequestService
https://code.google.com/p/simplesamlphp/issues/detail?id=579
Fix for Issue 580:	SAML2 Static Analysis] AuthnAuthorityDescriptor faulty initialisation of AssertionIDRequestService
https://code.google.com/p/simplesamlphp/issues/detail?id=580
Fixes Issue 581:	[SAML2 Static Analysis] PDPDescriptor faulty initialisation of AssertionIDRequestService
https://code.google.com/p/simplesamlphp/issues/detail?id=581
Removed unnecessary check (a foreach will not complain about empty arrays).
Fixed initialisation before use.
PHPDoc fixes: parameters and return types
PHPDoc: Added @throws annotation
Improved indentation
Improved whitespace
Fixed Issue 582:	[SAML2 Static Analysis] Possible fatal error on use of HTTPArtifact Binding without SAMLArt URL parameter
https://code.google.com/p/simplesamlphp/issues/detail?id=582
Minor refactor: rename variable to proper camelCase
Fixed return types