Deprecate the 'property …:' syntax, as suggested in #462

docs: Fix typos.

docs: Remove duplicated words.

Add a pass transforming Python-style properties in cdef class into Cython-style properties

This makes properties work properly in cdef classes, and gives them the
exact same AST as the “property something:” blocks, whose syntax should
probably be deprecated now.

Fixes T264.

Normalize filenames when calling parse_dependencies()

Conflicts:
	CHANGES.rst

Add missing decorators.

Fix typo.