…ist even if it was already, thus creating the wrong behaviour when pressing ReleaseNotes for versions of the same major release.Make the logic for finding the comparison version for the alpha release notes more verbose.

…ion anymore; so change the url logic for that. Update the settings option text in UI

…rPro# Conflicts:#UnityLauncherPro/Tools.cs

…sion selected in't supported by the alpha release notess sites. Split cumulative and non-cumulative OpenReleaseNotes function for better clarity.