dev-haskell/dns-1.0.0: manually set deps for ghc >= 7 and allow one of the test suites to run.
net-misc/haeredes-0.2.0: run only non-network tests.
x11-misc/xmonad-extras: add missing hlist depend for USE=perwindow (found by t3eblinder)

Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>