Added sections to gallery of examples

Modified travis_script.sh to account for the new structure of the gallery

Added README.txt files in directories of gallery examples

Fixed references to gallery images in user guide pages

Fixed broken links

doc/examples/edges/plot_shapes.py

@@ -0,0 +1,97 @@
+"""
+======
+Shapes
+======
+
+This example shows how to draw several different shapes:
+
+ - line
+ - Bezier curve
+ - polygon
+ - circle
+ - ellipse
+
+Anti-aliased drawing for:
+
+ - line
+ - circle
+
+"""
+import math
+import numpy as np
+import matplotlib.pyplot as plt
+
+from skimage.draw import (line, polygon, circle,
+                          circle_perimeter,
+                          ellipse, ellipse_perimeter,
+                          bezier_curve)
+
+
+fig, (ax1, ax2) = plt.subplots(ncols=2, nrows=1, figsize=(10, 6))
+
+
+img = np.zeros((500, 500, 3), dtype=np.double)
+
+# draw line
+rr, cc = line(120, 123, 20, 400)
+img[rr, cc, 0] = 255
+
+# fill polygon
+poly = np.array((
+    (300, 300),
+    (480, 320),
+    (380, 430),
+    (220, 590),
+    (300, 300),
+))
+rr, cc = polygon(poly[:, 0], poly[:, 1], img.shape)
+img[rr, cc, 1] = 1
+
+# fill circle
+rr, cc = circle(200, 200, 100, img.shape)
+img[rr, cc, :] = (1, 1, 0)
+
+# fill ellipse
+rr, cc = ellipse(300, 300, 100, 200, img.shape)
+img[rr, cc, 2] = 1
+
+# circle
+rr, cc = circle_perimeter(120, 400, 15)
+img[rr, cc, :] = (1, 0, 0)
+
+# Bezier curve
+rr, cc = bezier_curve(70, 100, 10, 10, 150, 100, 1)
+img[rr, cc, :] = (1, 0, 0)
+
+# ellipses
+rr, cc = ellipse_perimeter(120, 400, 60, 20, orientation=math.pi / 4.)
+img[rr, cc, :] = (1, 0, 1)
+rr, cc = ellipse_perimeter(120, 400, 60, 20, orientation=-math.pi / 4.)
+img[rr, cc, :] = (0, 0, 1)
+rr, cc = ellipse_perimeter(120, 400, 60, 20, orientation=math.pi / 2.)
+img[rr, cc, :] = (1, 1, 1)
+
+ax1.imshow(img)
+ax1.set_title('No anti-aliasing')
+ax1.axis('off')
+
+
+from skimage.draw import line_aa, circle_perimeter_aa
+
+
+img = np.zeros((100, 100), dtype=np.double)
+
+# anti-aliased line
+rr, cc, val = line_aa(12, 12, 20, 50)
+img[rr, cc] = val
+
+# anti-aliased circle
+rr, cc, val = circle_perimeter_aa(60, 40, 30)
+img[rr, cc] = val
+
+
+ax2.imshow(img, cmap=plt.cm.gray, interpolation='nearest')
+ax2.set_title('Anti-aliasing')
+ax2.axis('off')
+
+plt.show()