Fix CP#33904 - PythonDictionary.Contains(KeyValuePair) doesn't check value.

(cherry picked from commit da3cec10ca344a1c39b35b8bb2d8c1b1bbf67902)
Fix #95: Restrict platforms the P/Invoke SetEnvironmentVariable.

Only platforms with native code support should be using P/Invoke.

(cherry picked from commit a2958123bc3ab824c5ba8c5f09839fe934973393)
Fix 24276

- Added check for correct types as well as for null (None) and generate the correct error messages.

(cherry picked from commit b21758ce2507421a94b57982777258fa5f0611df)
Fix 26676

- Added check for application/zip in check for the type of the script.

(cherry picked from commit 67a18d21b4468913d4513aa393f8e18eed6c2a1b)
Add test files to .gitignore
Implement Python issue 9666 http://bugs.python.org/issue9666

hasattr shouldn't swallow all exceptions.  Handling AttributeError
is handled by TryGetBoundAttr

Feature is only enabled when -X:Python30 is passed.

(cherry picked from commit 5ae039a7b2aeb5726fc6dd05aa17c143b96022a7)