Issue 1244: implement command to display the version of the running Agda
Issue 1244: Release notes
[ issue 1246 ] Fixed by using the tag v0.8 from the standard library

The fix requires running `make up-to-date-std-lib` before running
`make library-test` when changing between the master and the
maintenance branches.

N.B. After this commit, the maint-2.4.0 branch is 1 commit ahead from
the master branch, so the maint-2.4.0 branch shouldn't be merged in
the master branch.
Merge pull request #10 from fredrikNordvallForsberg/issue1244

Issue1244: Command to display Agda version in Emacs
Issue 1244: make it possible to check version without loading the file
Merge branch 'issue1244' of git://github.com/fredrikNordvallForsberg/agda into fredrikNordvallForsberg-issue1244
Merge branch 'fredrikNordvallForsberg-issue1244'
[ tiny refactor ] A use of addContext.
Merge branch 'maint-2.4.0' of github.com:agda/agda into maint-2.4.0
Merge branch 'maint-2.4.0'
[ merge maint ] restored Makefile goal up-to-date-std-lib for master.
Merge remote-tracking branch 'upstream/master'