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/segmentation/plot_regionprops.py

@@ -0,0 +1,49 @@
+"""
+=========================
+Measure region properties
+=========================
+
+This example shows how to measure properties of labelled image regions.
+
+"""
+import math
+import matplotlib.pyplot as plt
+import numpy as np
+
+from skimage.draw import ellipse
+from skimage.measure import label, regionprops
+from skimage.transform import rotate
+
+
+image = np.zeros((600, 600))
+
+rr, cc = ellipse(300, 350, 100, 220)
+image[rr, cc] = 1
+
+image = rotate(image, angle=15, order=0)
+
+label_img = label(image)
+regions = regionprops(label_img)
+
+fig, ax = plt.subplots()
+ax.imshow(image, cmap=plt.cm.gray)
+
+for props in regions:
+    y0, x0 = props.centroid
+    orientation = props.orientation
+    x1 = x0 + math.cos(orientation) * 0.5 * props.major_axis_length
+    y1 = y0 - math.sin(orientation) * 0.5 * props.major_axis_length
+    x2 = x0 - math.sin(orientation) * 0.5 * props.minor_axis_length
+    y2 = y0 - math.cos(orientation) * 0.5 * props.minor_axis_length
+
+    ax.plot((x0, x1), (y0, y1), '-r', linewidth=2.5)
+    ax.plot((x0, x2), (y0, y2), '-r', linewidth=2.5)
+    ax.plot(x0, y0, '.g', markersize=15)
+
+    minr, minc, maxr, maxc = props.bbox
+    bx = (minc, maxc, maxc, minc, minc)
+    by = (minr, minr, maxr, maxr, minr)
+    ax.plot(bx, by, '-b', linewidth=2.5)
+
+ax.axis((0, 600, 600, 0))
+plt.show()