Util.Interact: fix build failure against readline
Util.Interact: fix build failure against readline


On ghc with both readline and editline enabled fails thusly:
[ 84 of 182] Compiling Util.Interact    ( src/Util/Interact.hs, src/Util/Interact.o )

src/Util/Interact.hs:41:5:
    Not in scope: ‘setCompletionEntryFunction’

src/Util/Interact.hs:42:10:
    Not in scope: ‘readline’
    Perhaps you meant one of these:
      ‘readLine’ (line 40), ‘readFile’ (imported from IO)

src/Util/Interact.hs:46:19: Not in scope: ‘addHistory’
src/Util/Interact.hs:154:29: Not in scope: ‘addHistory’
src/Util/Interact.hs:188:19: Not in scope: ‘addHistory’

hvr/jhc,hvr/jhc,hvr/jhc,shinnya/jhc-mirror,shinnya/jhc-mirror,hvr/jhc,shinnya/jhc-mirror,shinnya/jhc-mirror