"Enable" a few modules that are not available on all platforms

Author: BCSharp

tests/IronPython.Tests/Cases/CPythonCasesManifest.ini

@@ -472,10 +472,6 @@ NotParallelSafe=true # Creates/deletes a directory with static name 'xx'
 [CPython.test_glob]
 RunCondition=NOT $(IS_POSIX) # TODO: figure out
 
-[CPython.test_grp]
-RunCondition=$(IS_POSIX)
-Reason=Only valid for Unix
-
 [CPython.test_httplib] # IronPython.test_httplib_stdlib
 Ignore=true
 Reason=Blocking
@@ -713,7 +709,7 @@ Reason=Blocking
 [CPython.test_posix]
 RunCondition=$(IS_POSIX)
 Ignore=true
-Reason=unittest.case.SkipTest: No module named 'posix'
+Reason=AttributeError: module 'posix' has no attribute 'chown'
 
 [CPython.test_posixpath]
 Ignore=true
@@ -729,10 +725,6 @@ Reason=unittest.case.SkipTest: No module named 'fcntl'
 [CPython.test_pulldom]
 Ignore=true
 
-[CPython.test_pwd]
-RunCondition=$(IS_POSIX)
-Reason=Only valid for Unix
-
 [CPython.test_py_compile]
 Ignore=true
 Reason=NotImplementedError: sys.implementation.cache_tag is None