merge openfsharp changes

closes #255

commit d385f25
Author: enricosada <[email protected]>
Date:   Mon Feb 23 15:50:35 2015 +0100

    fix Assert.AreEqual arguments (first is expected value, second is actual value)

commit 172c363
Author: enricosada <[email protected]>
Date:   Fri Feb 20 18:35:54 2015 +0100

    merge openfsharp changes

commit aea137d
Author: enricosada <[email protected]>
Date:   Fri Feb 20 17:24:23 2015 +0100

    fix test

    the ordinal string comparison is implementation specific, only checks
    with less than 0, 0 and greater than 0 are meaningful

Author: enricosada