hough deprecated -> hough_line
hough_circle (cython)
add unittest for hough_circle
import hough_line instead of hough
remove unecessary global import
PEP8
update contrib
hough deprecated -> hough_line
hough_circle (cython)
PEP8
Merge branch 'hcircle' of github.com:sciunto/scikit-image into hcircle

Conflicts:
	skimage/transform/_hough_transform.pyx
	skimage/transform/hough_transform.py