[Python 3] Invalid type in validation of user property sheet values

[mliebischer]

Just found a Python 3 incompatibility at:

Products.PlonePAS/src/Products/PlonePAS/sheet.py

Lines 62 to 64 in e988432

	PropertySchema.addType(
	'long',
	lambda x: x is None or isinstance(x, long)

The data type long does not exists anymore in Python 3. long has become int with Python 3.

Possible fix for Python 2 and 3:

PropertySchema.addType(
    'long',
    lambda x: x is None or isinstance(x, six.integer_types)
)

From six documentation:

six.integer_types
Possible integer types. In Python 2, this is long and int, and in Python 3, just int.