Move high-level sleep function to Control.Timeout
Add threaded tests
Support for exceptions 0.6
Bump version, update changelog
Merge branch 'exceptions-release'

Conflicts:
	src/Control/Timeout.hs
Fix compile error in test suite.

tests/Control/Timeout/Tests.hs:23:76:
    No instance for (Num (Positive NominalDiffTime))
      arising from the literal ‘1000’
    In the second argument of ‘(<)’, namely ‘1000’
    In the second argument of ‘suchThat’, namely ‘(< 1000)’
    In the second argument of ‘($)’, namely
      ‘suchThat arbitrary (< 1000)’