newton_sloprs for polynomial over ZpCA requires a prime, and newton_polygon doesn't exist

[robharron]

Here's the bug:

R = PolynomialRing(ZpCA(5), 'x')
sage: x = R.gen()
sage: f = x^2 + 1
sage: f.newton_slopes()
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-79-687b034aeac7> in <module>()
----> 1 f.newton_slopes()

TypeError: newton_slopes() takes exactly one argument (0 given)
sage: f.newton_polygon()
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-87-e7bcefa164b7> in <module>()
----> 1 f.newton_polygon()

/Users/rharron/Programming/sage/local/lib/python2.7/site-packages/sage/structure/element.so in sage.structure.element.Element.__getattr__ (sage/structure/element.c:3527)()

/Users/rharron/Programming/sage/local/lib/python2.7/site-packages/sage/structure/misc.so in sage.structure.misc.getattr_from_other_class (sage/structure/misc.c:1488)()

AttributeError: 'Polynomial_padic_flat' object has no attribute 'newton_polygon'

ZpCR and Qp work fine. The problem appears to be that polynomials over ZpCA don't know they're over a p-adic ring.