Merge branch 'hotfix/1.22.14' into stable
clarify error message when creating gemset on system ruby, fix #2241
make sure groupadd an be found in standard paths, fix #2242
improve checking for rubinius head version, update #2235
Fixed a few typos in upgrade-notes.txt, closes #2238
1.22.15
Merge branch 'master' into hotfix/1.22.15
Merge branch 'hotfix/1.22.15'