Improve rel notes

[skip ci]

Author: JeroenDeDauw

RELEASE-NOTES.md

@@ -3,9 +3,8 @@
 ## Version 2.6.0 (dev)
 
 * Empty strings are now detected as invalid in the `SiteLink` constructor
-* Fixed `SnakList` constructor silently ignoring non-iterable inputs
-* Fixed `AliasGroup::equals` and `Term::equals` returning true for fallback objects
-* Fixed `EntityIdValue::unserialize` accidentally returning itself
+* The `SnakList` constructor now throws an `InvalidArgumentException` when getting a non-iterable input
+* The `AliasGroup::equals` and `Term::equals` methods no longer incorrectly return true for fallback objects
 
 ## Version 2.5.0 (2014-01-20)