Set background 1 so that the template has values equally-above and -below the mean image value. This change makes the template results left-right symmetric, which may reduce confusion.
This is a major revision that removes the `method` parameter of `match_template` and uses a new normalization method.
Note that the example result is different with this new normalization.
Remove `integral_images` and `integral_image_sqr` from _template.pyx in favor of calls to `skimage.transform.integral_image`.
This change required `match_template` arguments ("image" and "template") to be changed from float to double.
After this change, the template test runs about 25% slower.
This commit takes the template matching implementation from holtzhau/template (Pull Request #13) and converts the code to use the new package name (scikits.image --> skimage).
Johannes Schönberger