ENH: Added chkfinite flag to scipy.linalg
TESTS: Added tests for the chkfinite flag
Name change: chkfinite now check_finite
BLD: Add Tox support

* Adapted from Numpy
BLD: Include Tox support in source distributions
Fixed allclose call in normalize() of filter_design.py and added a test so check the output against the same filter coefficients from MATLAB
Added query_ball_point and related tests to scipy.spatial.cKDTree.
Fixed glitch in scipy.spatial.cKDTree.query_ball_point when p == infinity
ENH: Add weighted logsumexp as logsumexp_b
Added query_ball_tree to scipy.spatial.cKDTree
Added scipy.spatial.cKDTree.query_pairs(); simplified logic of scipy.spatial.KDTree.query_pairs()
Added sparse_distance_matrix to scipy.spatial.cKDTree
Added count_neighbors to scipy.spatial.cKDTree
ENH: fix a number of Cython issues in ckdtree.pyx, plus a speed improvement.

Main changes:

- Integer sizes are correct for 32 and 64 bit (it was totally confused)
  and npy_intp are used consistently.
- np.float64_t instead of double
- All variables are properly declared (many were left undeclared).
- All for loops with a range are Cython loops (none of Patrick's loops
  were correct...).
- Python exceptions propagate correctly through cdef functions.
- Memory leaks are prevented with try/finally.
- MemoryError is raised on malloc or realloc failure (Cython handles
  "raise MemoryError" correctly).
- PyArray_DATA is used for future compatibility with NumPy.
- Made sure the common case of Euclidian distance is processed faster.
STY: some PEP8 fixes in ckdtree.pyx
GEN: regenerate spatial/ckdtree.c
BUG: fix some bugs in ckdtree.pyx; in-place array altering and C long usage.
GEN: regenerate spatial/ckdtree.c
Experiment to enhance maintainability (only query_ball_tree for now)
npy_intp_dtype -> np.intp_t and other int enhancements

- All types that should correspond to np.intp now use np.intp_t uniformly,
  as per pv and sturla's comments
- Added a note on 64-bit cleanliness as I understand it now
- Refactored adding int tuples to sets and ints to list as per Sturla's
  suggestion on mailing list