[ release notes ] Added information about renaming of modules
[ releases ] Minor changes

* Push all the changes and the new tag simultaneously.
* Update Agda wiki after removing release-specific information.
Preparation for the release of version 0.8.1
Removed release-specific information
Replaced abstract + NO_TERMINATION_CHECK by NON_TERMINATING.
[ releases ] Fixed instruction
[ releases ] Updated information related to the Agda wiki
Merge branch 'master' of github.com:Agda/agda-stdlib
[ releases ] Missing change
[auto] merge master into gh-pages
[auto] updated html listings