Add list of not subclassable class

llvm tier: reduce scratch size

With the new frame introspection we don't need to save additional space for spilling vars which live in regs (except for deopts).
And for deopts we will never need more scratch than the one required for spilling the args.

Disable lxml objectify tests

Fix imp.load_module if the module already exists and ban creating instances of None type

Fix long(None) and 	bug inside getattrEntry() which made test_decimal fail

The cpython decimal test triggered this bug and works now. (But I had to add the correct version of the test)

Two minor problem which found in NumPy tests

Fix minor compatibility issues

add support for avro

enable PyStringObject and remove some workarounds inside the numpy patch

@rudi-c #1027 numpy patch with a small fix

By checking for the error state before the chosen CF call, we
know that it's not the CF call that set the error state.

Allow widths represented by subclasses of int and throw an exception
instead of aborting if the wrong types are given.

Also some minor cleanup of the NumPy test script.

Some of the patches are no longer necessary, as issues have
been fixed.