Fix for out of bounds error in RBM  with odd # of rows

Fixes out of bounds error in RBM with odd numbered matrix rows due to
gen_even_slices generating even slices that overshoot bounds of matrix.

```
/usr/local/lib/python2.7/dist-packages/sklearn/neural_network/rbm.pyc
in fit(self, X, y)
    310
    311             for batch_slice in batch_slices:
--> 312                 pl_batch = self._fit(X[batch_slice], rng)
    313
    314                 if verbose:

/usr/lib/python2.7/dist-packages/scipy/sparse/csr.pyc in
__getitem__(self, key)
    279
    280         elif isintlike(key) or isinstance(key,slice):
--> 281             return self[key,:]
#[i] or [1:2]
    282         else:
    283             return self[asindices(key),:]
#[[1,2]]

/usr/lib/python2.7/dist-packages/scipy/sparse/csr.pyc in
__getitem__(self, key)
    239                 #[1:2,??]
    240                 if isintlike(col) or isinstance(col, slice):
--> 241                     return self._get_submatrix(row, col)
#[1:2,j]
    242                 else:
    243                     P = extractor(col,self.shape[1]).T
#[1:2,[1,2]]

/usr/lib/python2.7/dist-packages/scipy/sparse/csr.pyc in
_get_submatrix(self, row_slice, col_slice)
    380         i0, i1 = process_slice( row_slice, M )
    381         j0, j1 = process_slice( col_slice, N )
--> 382         check_bounds( i0, i1, M )
    383         check_bounds( j0, j1, N )
    384

/usr/lib/python2.7/dist-packages/scipy/sparse/csr.pyc in
check_bounds(i0, i1, num)
    376                 raise IndexError( \
    377                       "index out of bounds: 0<=%d<%d, 0<=%d<%d,
%d<%d" %\
--> 378                       (i0, num, i1, num, i0, i1) )
    379
    380         i0, i1 = process_slice( row_slice, M )

IndexError: index out of bounds: 0<=113000<113966, 0<=114000<113966,
113000<114000
```