Broken Basemap rotpole projection

Nobody has claimed this yet.

Initally posted by a mistake to matplotlib/matplotlib
https://github.com/matplotlib/matplotlib/issues/9541
Here seems to be more relevant..

### Bug report

**Bug summary**

Basemap can't plot rotated-pole maps that cross rotated-grid's 0-th meridian

**Code for reproduction**
Here is a simple code that produce two maps for non-rotated grid (zero-rotation).
One does not cross Greenwich meridian another one does.

```python
# Paste your code here
#
#
#!/usr/bin/python
import matplotlib as mpl
mpl.use('AGG')

import matplotlib.pyplot as plt
import numpy as np
from mpl_toolkits.basemap import Basemap
import os

figname="okay.png"
fig = plt.figure()
bmap = Basemap(projection='rotpole',
llcrnrx=0, urcrnry=15,
urcrnrx=25, llcrnry=-15,
lon_0 = 0,
o_lon_p = 0.,
o_lat_p = 90.,
resolution='c')

bmap.drawmapboundary(fill_color='aqua')
bmap.fillcontinents(color='coral',lake_color='aqua')
bmap.drawcoastlines(linewidth=0.5)
bmap.drawparallels(np.arange(-20,20,10.))
bmap.drawmeridians(np.arange(-40,40,10.))

mpl.pyplot.savefig(figname)

figname="broken.png"
fig.clf()

bmap = Basemap(projection='rotpole',
llcrnrx=-25, urcrnry=15,
urcrnrx=25, llcrnry=-15,
lon_0 = 0,
o_lon_p = 0.,
o_lat_p = 90.,
resolution='c')

bmap.drawmapboundary(fill_color='aqua')
bmap.fillcontinents(color='coral',lake_color='aqua')
bmap.drawcoastlines(linewidth=0.5)
bmap.drawparallels(np.arange(-20,20,10.))
bmap.drawmeridians(np.arange(-40,40,10.))

mpl.pyplot.savefig(figname)

```

**Actual outcome**
Here are two maps.. The second one is obviously broken.

**Matplotlib version**
* Operating system: Python 2.7.1, python-matplotlib 1.5.1-1ubuntu1
* Matplotlib version: 1.5.1-1ubuntu1
* Python version: 2.7.1

Default Ubuntu 16.04.3 LTS installation

Start by running the provided reproduction script and comparing the two generated maps. Trace Basemap's rotpole projection handling for bounds crossing the rotated grid's zero meridian; done means both cases render map boundaries, coastlines, continents, parallels, and meridians correctly.

Written by the indexing model from the issue text.