[DotGNU]Fixing pnetlib test failures

[Rhys Weatherley]

There are a number of test failures in the pnetlib test suite,
which compiled with pnet.  Could we try to clean them up before
the 0.4.8 release?

    TestUriCanonicalize
    TestUriCheckHostName
    TestUriCheckSchemeName
    TestUriIsHexEncoding
    TestUriMakeRelative
    TestUriAuthority
    TestUriHost
    TestUriHostNameType
    TestUriIsDefaultPort
    TestUriPort
    TestUriQuery
    TestUriScheme
    TestUriUserInfo
    TestIPAddressHostToNetworkOrder
    TestIPAddressParse
    TestStringFormat

In the future, I would prefer that tests only be added to the
system if they succeed.  A failed test should be fixed immediately
by the person responsible for that area.  This way, if a future
change causes a test to stop working, we will know about it
immediately.

Cheers,

Rhys.