Support uniqueness types when executing IO actions in REPL
Fix for language-java 0.2.7
Merge pull request #1510 from soimort/uniqueness-execute

Support uniqueness types when executing IO actions in REPL
Install newer alex from Hackage for tests
Merge branch 'RyanGlScott-master'
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' into cplusplus-backend