Coordinates equality comparison fails for array values

```
In [1]: from astropy.coordinates import ICRS, Angle
In [2]: c1 = ICRS([1,2], [3,4], unit=('deg', 'deg'))
In [3]: c1 == c1
ERROR: ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all() [astropy.coordinates.coordsystems]
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-3-5768a5d8dcd9> in <module>()
----> 1 c1 == c1

/data/baffin/tom/git/astropy/astropy/coordinates/coordsystems.pyc in __eq__(self, other)
     50     def __eq__(self, other):
     51         try:
---> 52             return (self.latangle == other.latangle and
     53                     self.lonangle == other.lonangle and
     54                     self.distance == other.distance and

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()
```
Needs `np.all()` around the comparisons.