clr.accepts/clr.returns error issues

[slozier]

The error message for clr.accepts and clr.returns does not display types properly. For example:

import clr

@clr.accepts(int)
def test(x):
    return x

test("a")

fails with

AssertionError: argument 0 has bad value (got IronPython.Runtime.Types.PythonType, expected IronPython.Runtime.Types.PythonType)

Similarly with returns:

@clr.returns(int)
def test(x):
    return x

test("a")

AssertionError: bad return value returned (expected IronPython.Runtime.Types.PythonType, got IronPython.Runtime.Types.PythonType)

Also, AssertionError is an odd choice of error. Probably a TypeError would be more appropriate?

[slozier]

Fixed by #1449