Namespace-wrap the createvirtualnamespace call

Also fix `ut_repyv2api_virtualnamespacecontextsafety.py` to test the
proper functionality. (Following the namespace-wrap, it exhibited
an issue in in `namespace.py` which we need to discuss separately,
see SeattleTestbed#126)

Details about namespace wrapping:
* In `repy.py`, remove the addition of the non-wrapped `getresources`
  call to `usercontext`. (The properly wrapped definition was implemented
  in `namespace.py`'s `USERCONTEXT_WRAPPER_INFO` already, but `repy.py`
  overrode it.)
* In `namespace.py`, change the `SafeDict*` processors to inherit from
  class `ValueProcessor` rather than `ObjectProcessor`. This follows
  what the `Dict` processor does, and fixes the `virtualnamespace-eval`
  and `virtualnamespacecontextsafety` unit tests that failed with
  unwrapping errors when supplying a `dict` / `SafeDict` to the
  `VirtualNamespace` to be evaluated. The particular unit test
  errors were artifacts of how the `SafeDict*` processors inherited
  from `ObjectProcessor`, and looked like this:

"""
	Running: ut_repyv2api_virtualnamespace-eval.py              [ FAIL ]
--------------------------------------------------------------------------------
Standard error :
..............................Produced..............................
Internal Error
---
Uncaught exception!
---
Following is a full traceback, and a user traceback.
The user traceback excludes non-user modules. The most recent call is displayed last.

Full debugging traceback:
  "/private/tmp/repy_v2/RUNNABLE/namespace.py", line 1194, in wrapped_function
  "/private/tmp/repy_v2/RUNNABLE/namespace.py", line 1095, in _process_args
  "/private/tmp/repy_v2/RUNNABLE/namespace.py", line 283, in unwrap

User traceback:

Exception (with type 'exceptions.AttributeError'): SafeDict instance has no attribute '_wrapped__object'
---

..............................Expected..............................
None
--------------------------------------------------------------------------------
	Running: ut_repyv2api_virtualnamespacecontextsafety.py      [ FAIL ]
--------------------------------------------------------------------------------
Standard error :
..............................Produced..............................
Internal Error
---
Uncaught exception!
---
Following is a full traceback, and a user traceback.
The user traceback excludes non-user modules. The most recent call is displayed last.

Full debugging traceback:
  "/private/tmp/repy_v2/RUNNABLE/namespace.py", line 1194, in wrapped_function
  "/private/tmp/repy_v2/RUNNABLE/namespace.py", line 1095, in _process_args
  "/private/tmp/repy_v2/RUNNABLE/namespace.py", line 283, in unwrap

User traceback:

Exception (with type 'exceptions.AttributeError'): 'dict' object has no attribute '_wrapped__object'
---

..............................Expected..............................
None
--------------------------------------------------------------------------------
"""

namespace.py

@@ -572,7 +572,7 @@ def wrap(self, val):
 
 
 
-class SafeDict(ObjectProcessor):
+class SafeDict(ValueProcessor):
   """Allows SafeDict objects."""
 
   # TODO: provide a copy function that won't actually copy so that
@@ -585,7 +585,7 @@ def check(self, val):
 
 
 
-class DictOrSafeDict(ObjectProcessor):
+class DictOrSafeDict(ValueProcessor):
   """Allows SafeDict objects or regular dict objects."""
 
   # TODO: provide a copy function that won't actually copy so that

repy.py

@@ -120,7 +120,6 @@ def get_safe_context(args):
   #usercontext["createthread"] = emultimer.createthread
   #usercontext["sleep"] = emultimer.sleep
   #usercontext["getthreadname"] = emulmisc.getthreadname
-  usercontext["createvirtualnamespace"] = virtual_namespace.createvirtualnamespace
 
   # call the initialize function
   usercontext['callfunc'] = 'initialize'

testsV2/ut_repyv2api_virtualnamespacecontextsafety.py

@@ -1,21 +1,29 @@
 """
-This unit test checks that VirtualNamespace.evaluate() forbids an unsafe context.
+Verify that VirtualNamespace.evaluate() forbids an unsafe `context`.
+
+Specifically, the `context` that a VirtualNamespace object receives 
+must be a `SafeDict`, or parseable as one. This means that the 
+context's keys must be of type `str` (which we try to violate in this 
+test), avoid particular names / prefixes / components, etc.
+
+Using an unsafe context should raise a `ContextUnsafeError` when 
+evaluatinig the VirtualNamespace.
+
+See `safe.py` for what exactly a `SafeDict` is and isn't allowed to 
+do and to contain.
 """
 
 #pragma repy 
 
-# Small code snippet
-code = "log('Bad!')\n"
-
-# Get a VN
-VN = createvirtualnamespace(code, "Bad VN")
+# Create a virtual namespace with an empty piece of code and a telling name
+vn = createvirtualnamespace("", "Bad VN")
 
-# Create a malicious context
-context = {"__metaclass__":str}
+# Create a malicious context. (Its key should be `str`, not `int`.)
+context = {123: 456}
 
 # Try to evaluate this
 try:
-  VN.evaluate(context)
+  vn.evaluate(context)
 except ContextUnsafeError:
   pass
 else: