Improve mpoly context interface

src/flint/flint_base/flint_base.pxd

@@ -13,6 +13,9 @@ cdef class flint_mpoly_context(flint_elem):
     cdef public object py_names
     cdef const char ** c_names
 
+cdef class flint_mod_mpoly_context(flint_mpoly_context):
+    cdef readonly bint __prime_modulus
+
 cdef class flint_mpoly(flint_elem):
     cdef _add_scalar_(self, other)
     cdef _sub_scalar_(self, other)
@@ -54,8 +57,5 @@ cdef class flint_mat(flint_elem):
 cdef class flint_series(flint_elem):
     pass
 
-cpdef enum Ordering:
-    lex, deglex, degrevlex
-
-cdef ordering_t ordering_py_to_c(ordering: Ordering)
+cdef ordering_t ordering_py_to_c(ordering)
 cdef ordering_c_to_py(ordering_t ordering)