pyjnius should use "bound" methods instead of changing j_self

[obfusk]

pyjnius/jnius/jnius_export_class.pxi

Lines 815 to 822 in 3371e10

	def __get__(self, obj, objtype):
	if obj is None:
	return self
	# XXX FIXME we MUST not change our own j_self, but return a "bound"
	# method here, as python does!
	cdef JavaClass jc = obj
	self.j_self = jc.j_self
	return self

pyjnius/jnius/jnius_export_class.pxi

Lines 1079 to 1087 in 3371e10

	def __get__(self, obj, objtype):
	if obj is None:
	self.j_self = None
	return self
	# XXX FIXME we MUST not change our own j_self, but return a "bound"
	# method here, as python does!
	cdef JavaClass jc = obj
	self.j_self = jc.j_self
	return self

I suspect the current behaviour may not be thread-safe, but I haven't been able to reproduce #287.